43-45
ovaries
estrogen, progestins
Filtration occurs in the nephron at what structure?
Renal corpuscle (D)
From the anterior vena cava, blood flows to the _____.
Right atrium
Aldosterone is _____.
a steroid hormone that reduces the amount of fluid excreted in the urine
Aldosterone is ___.
a steroid hormone that reduces the amount of fluid excreted in the urine.
The posterior pituitary stores
and secretes hormones that are made in the hypothalamus
Aerobic Respiration General Chemical Equation
- C6H12O6 + 6O2 --> 6H2O + 6CO2 + energy
Posterior Pituitary
-Extension of the hypothalamus -Releases oxytocin
Arteries carry blood _____.
Away from the heart only.
) In each human menstrual cycle
One primary oocyte matures into an egg.
Androgens
_____ are the main male hormones.
testes
androgens
All hormones
are carried to target cells in the blood.
pineal gland
melatonin
posterior pituitary
oxytocin, ADH
Which of these glands secretes releasing hormones?
hypothalamus
Name that tissue: Hypothalamus
nervous
plasma creatinine
produced from the catabolism of creatine phosphate in skeletal muscle
Uric acid is more
energetically expensive produce than urea
A fruit is usually __________
a mature ovary
Aspirin and ibuprofen both
inhibit the synthesis of prostaglandins.
What is the usual site of the fertilization of an egg cell?
oviduct
The central nervous system is lacking in animals that have
radial symmetry.
Anabolic Pathways
- Glucose can be made from pyruvate - Fatty acids can be synthesized from acetyl CoA
Lymphocytes That Play a Huge Role in Adaptive Immunity
- T cells - B cells
c Level: 1
1. Which of the following fluid compartments contains the largest volume of water? A) plasma B) interstitial compartment C) intracellular compartment D) extracellular compartment E) lymph
d Level: 1
11. Serum electrolyte concentrations are most often expressed as A) mg %. B) mmHg. C) mg/dl. D) mEq/L. E) none of the above
amount of blood flowing through the kidney per minute?
1176 cc(ml)
The air pressure in Denver, Colorado, is about 83% of the air pressure in Miami Beach, Which is at about sea level. Given that the air pressure in Miami Beach is 760 mm Hg and oxygen makes up 21% of the air in Miami Beach, what are the percentage of oxygen and the partial pressure of oxygen in Denver, respectively?
21%; 21mm Hg.
How much more blood does heart move in minute when stimulated than when at rest? (5040mL and 30240mL)
25200mL
d Level: 1
3. Synovial fluid is a part of which of the following fluid compartments? A) plasma B) interstitial C) intracellular D) extracellular E) cytoplasm
When the air in a testing chamber is specially mixed so that its oxygen content is 10% and its overall air pressure is 400mm Hg, then PO2 is ____?
40mm Hg
The average pH for normal urine is about?
6.0
With an increase in steepness of Oxygen Saturation and PO2 in blood curve, one would expect _____.
A larger change in oxygen saturation of hemoglobin to a change in oxygen partial pressure.
hypokalemia.
A tumor in the adrenal cortex causes excessively high levels of aldosterone. The high aldosterone levels cause hyponatremia. acidosis. hypokalemia. hypocalcemia.
During a stressful interval
ACTH stimulates the adrenal cortex, and neurons of the sympathetic nervous system stimulate the adrenal medulla.
Glucocorticoids. In response to stress, ACTH stimulates the adrenal cortex to secrete glucocorticoids.
Adrenocorticotropic hormone (ACTH) triggers the release of _____ in response to stress.
Select the correct statement about osmoregulation.
All osmoconformers are marine animals.
increase, decrease
An increase in blood CO2 levels is followed by a(n) ____ in H+ ions and a(n) ____ in blood pH. decrease, decrease decrease, increase increase, increase increase, decrease
thirst.
Angiotensin II increases blood volume by stimulating thirst. vasodilatation. water movement into the cells. renal excretion of sodium.
) Adenocorticotroic hormone (ACTH) is made by the
Anterior pituitary.
Coffee drinkers urinate more frequently than those who do not drink coffee or other caffeinated beverages. Which of the following is a reasonable hypothesis for the effect of caffeine on your body?
Caffeine inhibits the release of antidiuretic hormone (ADH).
Which hormone is placed into the correct chemical class?
Calcitonin is a peptide hormone.
What type of blood vessels has the slowest velocity of blood flow?
Capillaries.
63) Natural selection should favor the highest proportion of juxtamedullary nephrons in which of the following species? A) a river otter B) a mouse species living in a tropical rain forest C) a mouse species living in a temperate broadleaf forest D) a mouse species living in the desert E) a beaver
D) a mouse species living in the desert
54) Glucose is removed from filtrate by A) secretion. B) diffusion. C) dialysis. D) active transport. E) osmosis.
D) active transport.
) M}llerian inhibitory substance (a polypeptide hormone) inhibits
Development of female reproductive organs in males.
Which of the following events occurs at the onset of the luteal phase of the menstrual cycle?
Development of the corpus luteum.
How can a hormone effect cells differently?
Different receptors Different signal transduction pathways
A thickening of the blood along with heart failure in otherwise healthy people has been observed with excessive use of ______.
Erythropoietin
Which of the following animals has a three-chambered heart?
Frog.
Which of the following is a difference between plants and fungi?
Fungi are heterotrophic, and plants are autotrophic.
A particular cell has half as much DNA as some other cells in a mitotically active tissue. The cell in question is most likely in
G1
Shortly after ingesting a big plate of carb-rich pasta, you measure your blood's hormone levels. What results would you expect, compared to before the meal?
High insulin, low glucagon
High cortisol levels will begin to cause ACTH levels to decline.
If both ACTH (adrenocorticotropic hormone) and cortisol levels increase, which of the following would occur? ACTH production is increased even more by positive feedback. High cortisol levels will begin to cause ACTH levels to decline. High ACTH levels will begin to cause cortisol levels to decline
A shift to the right of the oxygen-hemoglobin equilibrium curve represents _____.
Increased oxygen delivery to a tissue-representing a pH decrease-makes hemoglobin more likely to release oxygen to tissues with low pH.
correct
Normally, GFR increases very little when systemic blood pressure rises
Antidiuretic hormone (ADH)
regulates physiology and behavior
Which characteristic of the male reproductive system is not variable among animal species that reproduce sexually?
Presence of genitalia.
Which of the following statements is not true of hormones?
Some have only local effects on nearby cells.
Select the correct statement about feedback regulation in endocrine systems.
Some homeostatic control systems rely on pairs of negatively regulated hormone pathways, each counterbalancing the other.
Pluripotent hematopoietic stem cells
Stem cell in bone marrow that gives rise to all the cellular elements of the blood. INclude inate and adaptive
Which of the following statements correctly describes the relationship between the hypothalamus (H) and the anterior (AP) and posterior (PP) lobes of the pituitary?
The H communicates directly with the PP and indirectly with the AP through the circulatory system.
ADH production increases.
The collecting duct becomes more permeable to water when colloid osmotic pressure increases. ADH production increases. plasma osmolality decreases. aldosterone production decreases
Which of the following best describes the process of ventilation? 1) The movement of the respiratory medium past the respiratory surface 2) The diffusion of gases into and out of tissues when cellular respiration occurs 3) The diffusion of gases into and out of the circulatory system 4) The movement of oxygen gas through the blood of the circulatory system 5) The movement of carbon dioxide gas through the blood of the circulatory system
The movement of the respiratory medium past the respiratory surface
B. ACTH
The release of cortisol is stimulated by A. CRH B. ACTH C. aldosterone D. angiotensin
glomerulus and glomerular (Bowman's) capsule
The renal corpuscle consists of the
Protein receptor complexes then
act as transcription factors in the nucleus, regulating transcription of specific genes
The same hormone may have different effects on target cells that have
different receptors for the hormone; different signal transduction pathways
digestive system function
food processing (ingestion, digestion, absorption, elimination)
parathryoid hormone (PTH)
increases reabsorption of Ca2+
definition: osmotic pressure
pressure that water makes to equilibrate osmolality in 2 compartments
What would be an example of a stochastic event?
A severe storm. Stochastic means change, or random.
A. premature closing of the epiphyseal plates
A sign of pituitary dwarfism is A. premature closing of the epiphyseal plates B. massive enlargement of the thyroid gland C. glycosuria, polyuria, ketosis, and hyperglycemia D. exophthalmos, gynecomastia, and buffalo hump .,
40) Which one of the following is extremely important for water conservation in mammals? A) juxtamedullary nephrons B) Bowman's capsule C) urethra D) podocytes E) ureter
A) juxtamedullary nephrons
Which of the following statements best describes the actions of the hormone ADH of the nephron?
ADH causes the collecting duct to increase water reabsorption by the surrounding tissue under conditions of dehydration
hypothalamus; anterior pituitary
ADH is synthesized by the ____ while TSH is synthesized by the ____. kidney; thyroid posterior pituitary; thyroid hypothalamus; anterior pituitary kidney; anterior pituitary
Receptors for nonsteroid hormones are located in _____
Association with a cell's plasma membrane
Adrenal cortex
(outer portion) responds to endocrine signals, secretes mineralocorticoids and gluocorticoids
Different body cells can respond differently to the same peptide hormones because
) a target cell's response is determined by the components of its signal transduction pathways.
A nephron consists of a glomerulus and a long tubule that includes Bowman's capsule, the proximal tubule, the loop of Henle, and the distal tubule.
...
Osmolarity measures the moles of solute per liter of solution.
...
Passive transport is used to move molecules down a concentration gradient -- from where they are more concentrated to where they are less concentrated. Passive transport does not require energy from cells.
...
The kidneys concentrate urine by establishing an osmolarity gradient between the cortex and the medulla. Passive and active transport both play a role in this process.
...
Through active and passive transport, NaCl helps establish and maintain the osmolarity gradient.
...
Through osmosis, a form of passive transport, water responds to the osmolarity gradient by leaving the filtrate.
...
Through passive transport only, urea also helps establish and maintain the osmolarity gradient.
...
Under the influence of ADH more concentrated urine is produced and the body conserves water.
...
what are the 2 types of diabetes insipid us
1. hypothalamic = no secretion of ADH by hypothalamus 2. neprogenic = inappropriate renal response to ADH (mut of aquaporin 2 gene or mutation in ADH receptor)
Which barriers must Oxygen and Carbon Dioxide cross to pass between air and blood inside lungs?
1.) Epithelial Cells 2.) Extracellular fluid 3.) Capillary walls
a Level: 1
12. Water moves back and forth across the plasma membrane by the process of A) osmosis. B) filtration. C) facilitated diffusion. D) active transport. E) endocytosis.
Ovulation usually occurs on or about day _____ of a 28-day ovarian cycle.
14
b Level: 2
16. As the rate of sweat production increases, the amount of sodium lost in the urine A) increases. B) decreases. C) remains the same.
e Level: 1
72. Which of the following can play a role in buffering the pH of urine? A) ammonia B) bicarbonate ions C) phosphate ions D) A and B only E) A, B, C
a Level: 3
82. The increase in extracellular osmolality would cause A) water to move out of the cells. B) water to move into the cells. C) no change in the net movement of water into or out of the cells.
16) Why would a liver cell and a lung cell respond differently to the same steroid hormone? A) They have different receptor proteins within the cell. B) They have different acceptor proteins on the chromatin. C) Steroid hormones usually transmit signals that are antagonistic. D) The acceptor proteins are associated with different genes in the two kinds of cells. E) The hormone-receptor complex is transcribed and processed differently in the two kinds of cells.
C
50) Which of the following pairs of hormones do not have antagonistic effects? A) insulin and glucagon B) thyroid-releasing hormone and T3 and T4 C) parathyroid hormone and calcitonin D) follicle-stimulating hormone and luteinizing hormone E) aldosterone and atrial natriuretic factor
D
64) Which of the following is not a cardinal sign of diabetes mellitus? A) polyphagia B) polydipsia C) polyuria D) All of these are signs.
D
65) Which of the choices below is not a factor required for target cell activation by hormone receptor interaction? A) strength of the bond between the receptor and hormone B) blood levels of hormone C) number of receptor D) type of hormone
D
66) Which of these is the second of the three stages of cell signaling? A) reception B) transduction C) gene activation D) binding of a neurotransmitter to a plasma membrane receptor E) cell response
D
67) Growth factors are local regulators that A) are produced by the anterior pituitary. B) are modified fatty acids that stimulate bone and cartilage growth. C) are found on the surface of cancer cells and stimulate abnormal cell division. D) bind to cell-surface receptors and stimulate growth and development of target cells. E) convey messages between nerve cells.
D
hyperpolarization of cell membranes.
Decreased extracellular potassium levels cause cells to become more excitable. hyperpolarization of cell membranes. more action potentials to be generated. increased permeability of cell membranes
baroreceptors signal the hypothalamus to decrease ADH secretion
Elevated blood pressure under resting conditions results in increased urinary output because baroreceptors signal the hypothalamus to decrease ADH secretion. levated blood pressure stimulates renin secretion. the amount of angiotensin II formed is increased. aldosterone levels increase.
) In the human menstrual cycle, small quantities of ______ exert negative feedback on ______ release, and large quantities exert positive feedback.
Estradiol; luteinizing hormone
What problem does a freshwater fish have to deal with?
Excess water constantly entering their body (via gills). They have to excrete the water.
) The islets of Langerhans in the pancreas produce insulin and ______.
Glucagon
Analysis of a blood sample from a fasting individual who had not eaten for 24 hours would be expected to reveal high levels of _____.
Glucagon.
43) Depending on salt intake and water availability, humans can produce urine that is A) hyperosmotic to body fluids. B) hypoosmotic to body fluids. C) isoosmotic to body fluids. D) A and B are true. E) A, B, and C are true.
E) A, B, and C are true.
A. dissociate into anions and cations
Electrolytes A. dissociate into anions and cations B. generally have covalent bonds C. include glucose, urea, and creatine D. are usually organic compounds
You discover a new species of bacteria that grows in aquatic environments with high salt levels. While studying these bacteria, you note that their internal environment is similar to the salt concentrations in their surroundings. You also discover that the internal salt concentrations of the bacteria change as the salt concentration in their environment changes. The new species can tolerate small changes in this way, but dies from large changes because it has no mechanism for altering its own internal salt levels. What type of homeostatic mechanism is this species using to regulate its internal salt? levels?
Conformation
14) How is a cell's response to a water-soluble hormone amplified? A) regulation of intracellular hormone levels B) regulation of cell volume C) changes in the intracellular levels of cytokines D) regulatory proteins present inside of the cell E) regulation of the number of surface receptors
D
38) All of the following are steroid hormones except A) androgen. B) cortisol. C) estrogen. D) insulin. E) testosterone.
D
A. pH
Hyperventilation (breathing in and out more air than normal) during a panic attack causes an increase in blood ________. A. pH B. H+ C. partial pressure of CO2 D. partial pressure of CO2 and H+
Which of these glands secretes releasing hormones? hypothalamus adrenal cortex thymus ovaries testes
Hypothalamus; The hypothalamus secretes both releasing and inhibiting hormones
Making the collecting duct permeable to water results in the reabsorption of water.
...
Nephrons are positioned in the renal cortex and can extend into the renal medulla.
...
63) Insect brain hormone is most analogous to which of the following in humans? A) insulin from the pancreas B) parathyroid hormone from the parathyroid gland C) ADH from the posterior pituitary D) releasing hormones from the hypothalamus E) androgens from the adrenal cortex
D
You just received a freshwater aquarium as a gift and decide to add more fish. When you get to the pet store, you find that the most beautiful fish are saltwater animals, but you decide to buy them anyway. What will happen when you put the saltwater fish in a freshwater aquarium?
The cells of the fish will take up too much water, and the fish will die.
Abnormally reduced somatic growth (dwarfism) can be a consequence of decreased hormone secretion from the
anterior pituitary gland.
Extracellular pathogens such as viruses and bacteria in body fluids are attacked by ____
antibodies from plasma cells
Animals utilizing external fertilization are typically ____
aquatic animals
All seed plants _____.
are heterosporous
The kinetochores __
are sites at which microtubules attach to chromosomes
Pheromones serve many functions, including marking trails leading to
food, defining territories, warning of predators, and attracting potential mates
Cerebrospinal fluid can be described as all of the following except
formed from layers of connective tissue.
Osmoregulation in a freshwater fish
gain of water and some ions in food; uptake of salt ions by gills, osmotic water gain through gills; excretion of salt ions and large amounts of water in dilute urine from kidneys
For a neuron with an initial membrane potential at -70 mV, an increase in the movement of potassium ions out of that neuron's cytoplasm would result in the
hyperpolarization of the neuron.
Which of these is the functional unit of a kidney?
nephron
Which one of the following criteria is not required to induce Daphnia to switch from asexual to sexual reproduction?
the absence of males in the population
Saltatory conduction is a term applied to
jumping from one node of Ranvier to the next in a myelinated neuron.
A physician finds that a 16-year-old male patient, who has a very high-pitched voice and underdeveloped testes, has abnormally low levels of testosterone. What structure(s) might be the reason that this patient is producing such a low level of testosterone? 1. gonads 2. pituitary gland 3. adrenal gland 4. hypothalamus 5. thyroid gland
#1 and #2 and #4
Adaptive Immunity (Acquired Immune Response)
- A defense found only in vertebrates - Animals with adaptive immunity produce a vast arsenal of receptors, each of which recognizes a feature typically found only on a particular part of a particular molecule in a particular pathogen - Activated after the innate immune response and develops more slowly
Absorption Spectrum
- A graph plotting a pigment's light absorption versus wavelength
Molecular Recognition
- Detection of non-self - Receptor molecules bind specifically to molecules from foreign cells or viruses
How NAD+ Traps Electrons From Organic Molecules
- Enzymes called dehydrogenases remove a pair of hydrogen atoms (2 electrons and 2 protons) from the substrate (i.e. glucose) thereby oxidizing it - The enzyme delivers the 2 electrons along with 1 proton to its coenzyme NAD+ (the other proton is released as a hydrogen ion into the surrounding solution) to become NADH - Electrons lose very little of their potential energy when they are transferred from glucose to NAD+
Generation of T Cell Diversity
- Each person makes more than 10 million different T cell receptors (20,000 protein-coding genes in the human genome)
ATP Formation Statistics
- For each molecule of glucose degraded by carbon dioxide and water by cell respiration, the cell makes up to about 32 molecules of ATP (each with 7.3 kcal/mol of free energy)
Structure of Photosystem II
- Has two photosystem complexes side by side - Chlorophyll molecules are interspersed with protein subunits
Hydrogen/Electrons
- In general, organic molecules that have an abundance of hydrogen are excellent fuels because their bonds are a source of "hilltop" electrons whose energy may be released as these electrons "fall" down an energy gradient when they are transferred to oxygen
Linear Electron Flow
- Key to energy transformation - Flow of electrons through the photosystems and other molecular components built into the thylakoid membrane
Humoral Immune Response
- Occurs in the blood and lymph - Antibodies help neutralize or eliminate toxins and pathogens in the blood and lymph - Includes a primary and secondary immune response (memory cells enable secondary immune response)
Eosinophils
- Often found beneath muscosal surfaces - Have low phagocytic activity, but are important in defending against multi-cellular invaders (such as parasitic worms) by discharging destructive enzymes when parasites are encountered
Alcohol Fermentation
- Pyruvate is converted to ethanol (eythl alcohol) in two steps 1) The release of CO2 from the pyruvate, which is converted to the two carbon compound acetaldehyde 2) Acetaldehyde is reduced by NADH to ethanol which regenerates the supply of NAD+ needed for the continuation of glycolysis - Bacteria and yeast (fungus) use this
Chlorophyll b
- Slight structural difference between a and b causes the two pigments to absorb slightly different wavelengths in the red and blue parts of the spectrum - Olive green
Photoautotroph
- Specifically, plants are photoautotrophs, organisms that use light as a source of energy to synthesize organic substances
Cells Most Often Communicate
- Using chemical signals
What is the typical osmolarity of human blood?
300 mosm/L
d Level: 2
29. Which of the following would be expected to cause hyponatremia? A) high intake of sodium B) increased aldosterone production C) increased urine output D) increased ADH production E) decreased ADH production
What number and types of chromosomes are found in a human somatic cell?
44 autosomes and 2 sex chromosomes
Structure of ADH receptor
7 transmembrane receptors coupled to G protein
a Level: 1
7. The predominant intracellular cation is A) potassium. B) sodium. C) calcium. D) magnesium. E) chloride.
b Level: 2
80. Prolonged vomiting of stomach contents will result in A) metabolic acidosis. B) metabolic alkalosis. C) respiratory acidosis. D) respiratory alkalosis. E) none of the above
integumentary systems components
skin and its derivatives (hair, claws, skin glands)
Which of the following is not a component of an insect's defense against infection?
activation of natural killer cells
Glucose is removed from filtrate by
active transport
Glucose is removed from filtrate by _____.
active transport
correct
Angiotensin II and atrial natriuretic peptide help regulate GFR
) ______ during the ______ trimester of pregnancy has the greatest risk for a woman giving birth to a baby with fetal alcohol syndrome (FAS).
Binge drinking; first
A. hypophyseal portal veins
Blood passes in a direct route from the hypothalamus to the anterior pituitary gland through the A. hypophyseal portal veins B. superior hypophyseal arteries C. carotid artery D. posterior hypophyseal veins
C. phosphate
Bone, DNA, RNA, ATP, and cell membranes all have one thing in common. They all contain _____ . A. sulfur B. calcium C. phosphate D. magnesium
The renal corpuscle consits of...
Bowman's capsule and the glomerulus
An example of antagonistic hormones controlling homeostasis is
insulin and glucagon in glucose metabolism.
what mineral corticoid is the precursor for aldosterone
DOC (deoxycorticosterone)
Which pituitary secretion stimulates sperm production?
FSH
What pituitary hormones are involved in regulating the human menstrual cycle?
FSH and LH
a pressure gradient.
Filtrate flows through the nephron because of gravity. a pressure gradient. a concentration gradient. peristaltic contractions.
Marine vertebrates are _____ to their environment.
Hypotonic.
DNA
In their mechanism of action, a difference between lipid-soluble and water-soluble hormones is that lipid-soluble hormones bind to an intracellular receptor and this hormone-receptor complex binds to ______.
metabolic alkalosis.
Ingesting large amounts of sodium bicarbonate can lead to metabolic acidosis. metabolic alkalosis. respiratory acidosis. respiratory alkalosis.
aldosterone binds what type of receptor?
Intracellular (bc its steroid) leading to activation of gene expression
1,25-Dihydroxy vitamin D3, which is the active form of vitamin D, is made in the
Kidneys.
D. sodium
Levels of which of the following are regulated by aldosterone?A. carbonic acid B. glucose C. magnesium D. sodium
In which region of the nephron is a steep osmotic gradient created?
Loop of Henle.
Why are marine fish essentially living in a desert, from an osmotic standpoint?
Marine fish are losing water to the environment. They are surrounded by water, by after drinking the water, they have to excrete the salts.
Gymnosperms were most abundant during the _____.
Mesozoic
MI
Myocardial infarction =heart attack
is most of Na reabsorption in kidney dependent on aldosterone?
NO, 95% occurs before collecting tubule, independent of aldosterone
The two primary solutes affecting osmolarity are
NaCl and urea
Against viruss
Natural Killer Plasmacytoid dendritic cells
parathyroid glands
PTH
Components of ECF
Plasma (25%) and Intersititial fluid (75%)
ADH is secreted from...
Posterior pituitary
From the capillaries of the abdominal organs and hind limbs, blood flows to the ____.
Posterior vena cava
the best definition of an endotherm is an animal that _____.
Produces adequate heat to warm its own tissues.
Which function is not performed by the male reproductive system?
Production and storage of oogonia..
Materials are returned to the blood from the filtrate by which process?
Selective reabsorption
The heating system maintains room temperature at or near a particular value, know as the _____.
Set point.
What is the most likely explanation for why Daphnia switch from asexual to sexual reproduction when certain environmental conditions deteriorate?
Sexual reproduction creates individuals that are more genetically diverse, thus increasing the likelihood of some members surviving hard times.
(Relation to Fick's Law) The epithelium of alveoli is thin.
Small D.
African lungfish, which are often found in small stagnant pools of fresh water, produce urea as a nitrogenous waste. What is the advantage of this adaptation?
Small stagnant pools do not provide enough water to dilute the toxic ammonia.
C. extracellular fluid
The cerebrospinal fluid in the brain is classified as A. intracellular fluid B. lymph C. extracellular fluid D. plasma
C. within cells
The largest volume of body fluid is located A. in plasma B. in lymph C. within cells D. between cells
kidneys.
The main regulator of serum phosphate levels is a transport process in the liver. kidneys. pancreas. small intestine.
B. attach to specific transport proteins
Upon entering the blood, steroid and thyroid hormones A. circulate freely as separate molecules B. attach to specific transport proteins C. combine with lipid carrier molecules D. react chemically with carbohydrates to inactivate them
Where does a human fetus develop?
Uterus.
most important ADH receptor is...
V2 receptor in kidney collecting duct cells (Gas receptor)
Within a normally functioning kidney where can blood be found?
Vasa recta
Steroids
Which type of hormone is lipid soluble?
A human who has no access to freshwater but is forced to drink seawater instead ______?
Will dehydrate (excreting more water molecules than taken in because of the high load of ion ingestion.)
uncontrollable micturition.
With aging, a loss of inhibitory action potentials to the sacral region of the spinal cord results in increased bladder capacity. voluntary micturition. continuous dribbling of urine. uncontrollable micturition.
Aldosterone causes K excretion via what mechanism
activation of ROMK channels which pump K out of cell
Testosterone is an example of
an androgen.
Human survival literally depends on the produce of _____.
angiosperms
tissues
cells organized into this
Which process in the nephron is least selective? Select one: a. reabsorption b. salt pumping by the loop of Henle c. secretion d. filtration e. active transport
d. filtration
What is the secondary stimuli for ADH release?
decrease in blood pressure/volume
Which of the following shows a brain structure correctly paired with one of its primary functions?
frontal lobe-decision making
What is the functional unit of a kidney?
nephron
Neurosecretory cells produce hormones that are stored in the
posterior pituitary
The major difference between angiosperms and gymnosperms comes from the _____.
presence or absence of a protective covering over the ovule
Steroid hormone-receptor complexes act in
the nucleus
Steroid hormone-receptor complexes act in _____.
the nucleus
thyroid gland
thyroid hormone T3 and T4, calcitonin
eosinophils
white blood cell that are responsible for combating infection by parasites in vertebrates Attack antibody coasted parasites
Sperm exit a male's body via the _____.
urethra
What effect does ADH have on the urine?
More concentrated urine
Decrease the saturation of the fatty acids on a particular type of phospholipid would result in the formations of _____.
More fluid bilayers. Unsaturated fatty acids have kinds that prevent tight packing of the hydrophobic tails. This increases the fluidity and permeability of the membrane.
bones.
Most of the calcium in the body is in the bones. plasma. kidneys. GI tract
Neuroendocrine
Neuroendocrine signals are also hormones.
potassium and chloride are cotransported with sodium across the apical membrane
In the ascending limb of the loop of Henle, water can easily enter or leave. potassium and chloride are cotransported with sodium across the apical membrane. calcium ions are actively transported across the basal membrane. potassium is concentrated in the filtrate.
Against bacteria
Monocytes which different into macrophages upon entering tissues from the blood Macrophages Neutrophils
C. pineal gland
Jet lag is associated with the changes in secretion of a hormone from the A. hypothalamus B. anterior pituitary gland C. pineal gland D. thyroid gland
(Relation to Fick's Law) Alveoli present a large surface area.
Large A.
Nitrogenous wastes excreted depend on
an animal's evolutionary history, habitat, environment of the animal egg
hormones are
chemical signals between cells, transported in blood or hemolymph
In the male testis, LH causes Leydig cells to produce
testosterone
In a simple synapse, neurotransmitter chemicals are released by
the presynaptic membrane.
Steroid and peptide hormones typically have in common
their requirement for travel through the bloodstream.
What is the function of endocrine glands?
they release hormones into the bloodstream for distribution around the body
Cell-mediated immunity differs from humoral immunity because__
they respond differently to invaders
From the capillaries of the abdominal organs and hind limbs, blood flows to the _____.
Posterior vena cava.
Blood returns to the heart via the ____.
Pulmonary veins.
Blood returns to the heart via the _____.
Pulmonary veins.
Which of these facts provides the best support for the hypothesis that plants evolved from green algae?
The chloroplasts of plants and green algae all have both chlorophyll a and b.
pancreas
a gland located behind the stomach; insulin and glucagon
Steroid hormone-receptor complexes act in _____.
The nucleus; they effect transcription
A. brain
The pineal gland is located in the A. brain B. neck, near the thyroid gland C. upper chest region D. lower abdomen, near the bladder
sodium.
The predominant extracellular cation is bicarbonate. sodium. chloride. potassium.
aldosterone.
The primary regulator of plasma sodium concentration is renin. aldosterone. antidiuretic hormone (ADH). atrial natriuretic hormone.
As a person goes from erst to full-effort exercise, there is an increase in the _____.
Tidal Volume.
True or false? THe homeostatic system for blood calcium concentration is maintained by the hormones calcitonin and parathyroid hormone.
True
False. Lipid-insoluble hormones cannot cross the plasma membrane and get into the cell, so they must bind to receptors on the cell surface and transduce their signals through signal transduction pathways.
True or false? Lipid-insoluble hormones affect their target cells by binding to receptors inside the cell.
Antidiuretic Hormone (ADH)
What hormone promotes water retention by the kidneys?
Hormones act as a chemical signal between cells
What is a common feature of all hormones?
increases
When dilute urine is being formed, the osmolarity of the fluid in the tubular lumen ____ as it flows down the descending limb of the loop of Henle
When there is relaxation of arterial smooth muscle caused by nitric oxide, when growth factor stimulates the growth of embryonic cells, when cytokines play a role in immune responses, and when prostaglandins released from the placenta alter the excitability of the muscle of the uterus.
When is the action of a local regulator illustrated?
Fight-or-Flight Response
Which function below is not influenced by thyroid hormones? -rate of cellular respiration -growth rate -muscle tone -blood pressure maintenance -fight-or-flight response
D. relaxin
Which hormone is not produced in the male? A. inhibin B. testosterone C. FSH D. relaxin
Epinephrine and Norepinephrine. These hormones, secreted by the adrenal medulla, are responsible for the "fight or flight" response.
Which hormones are responsible for the "fight or flight" response to danger?
Renal autoregulation, neural regulation, and hormonal regulation
Which of the following are mechanisms that control GFR?
potassium ions
Which of the following are most likely to be actively secreted into the distal convoluted tubule? potassium ions. chloride ions. bicarbonate. amino acids.
weight gain
Which of the following characteristics is associated with hyposecretion of thyroid hormones? weight gain exophthalmos warm, flushed skin increased heartrate
C. hormones acts on muscles and glands only
Which of the following does not describe hormones in the body? A. they are mediator molecules released in one part of the body but regulating the activity of cells in other parts of the body B. most hormones enter interstitial fluid and then the bloodstream C. hormones acts on muscles and glands only D. hormones exert their effects by binding to receptors on or in the "target" cells
Enzymes break down thyroglobulin to release T3 and T4
Which of the following events occurs last? Enzymes break down thyroglobulin to release T3 and T4. T3 and T4 are stored within thyroid follicles. Iodine is bound to tyrosine molecules of thyroglobulin. Thyroglobulin is taken into thyroid cells by endocytosis.
plasma
Which of the following fluid compartments contains the smallest volume of water? plasma interstitial compartment intracellular compartment extracellular compartment
B. Receptors are located on the cell membrane
Which of the following is NOT characteristic of steroid hormones? A. They are lipid soluble B. Receptors are located on the cell membrane C. They act on the DNA level D. They work through intracellular receptors
Zinc-Finger. A zinc finger is a distinctive DNA-binding domain on some hormone receptors that is exposed when hormone-receptor complexes are formed.
Which of the following is a structure that allows hormone-receptor complexes to bind to specific DNA sequences? -Hormone-response element (HRE). -Promoter. -Zinc finger. -Enhancer.
Salivary
Which of the following is an exocrine gland? -islets of Langerhans -pituitary gland -adrenal gland -salivary gland
an increase in urine volume
Which of the following is most likely to happen to a group of students who relax by drinking a pitcher of their favorite beverage? an increase in urine volume an increase in urine osmolality an increase in ADH production increased aldosterone secretion
C. They are necessary for generation of action potentials
Which of the following is true concerning sodium ions?A. They represent about 90 percent of extracellular anions B. They combine with chloride ions in gastric glands to form hydrochloric acid C. They are necessary for generation of action potentials D. Excess ions are stored by the kidneys
B. calcitonin and parathyroid hormone
Which of the following produce antagonistic results? A. FSH and LH B. calcitonin and parathyroid hormone C. ADH and vasopressin D. oxytocin and prolactin
glomerulus
Which of the following structures is a capillary? glomerulus loop of Henle collecting duct Bowman's capsule
Estrogen
Which of these extracellular signal molecules could diffuse through a plasma membrane and bind to an intracellular receptor? -estrogen -epinephrine -cellulose -oxytocin -starch
Hypothalamus. The hypothalamus secretes both releasing and inhibiting hormones.
Which of these glands secretes releasing hormones? -hypothalamus -adrenal cortex -thymus -ovaries -testes
Epinephrine and Oxytocin
Which of these is a nonsteroid hormone? -estrogen -testosterone -both estrogen and testosterone -oxytocin -epinephrine and oxytocin
A. zona glomerulosa
Which region of the adrenal gland produces mineralocorticoids? A. zona glomerulosa B. zona fasciculata C. zona reticularis D. medulla
Which of the following is a structure that allows hormone-receptor complexes to bind to specific DNA sequences? Enhancer. Promoter. Zinc finger. Hormone-response element (HRE).
Zinc finger; A zinc finger is a distinctive DNA-binding domain on some hormone receptors that is exposed when hormone-receptor complexes are formed.
The nucleus and most of the organelles in a neuron are located in the Select one: a. axon terminals b. dendritic region c. cell body d. axon hillock. e. axon
c. cell body
The nucleus and most of the organelles in a neuron are located in the
cell body.
Helper T cells are part of ___
cell-mediated immune responses
Hormones are _____.
chemical signals between cells, transported in blood or hemolymph
Our understanding of mental illness has been most advanced by discoveries involving the
chemicals involved in brain communications.
Antidiuretic hormone (ADH) makes the _____ permeable to water.
collecting duct
renal pelvis
collects urine from the excretory tubules and passes it to the urinary bladder
renal corpuscle
combined glomerulus and glomerular capsule; where plasma is filtered
The renin-angiotensin-aldosterone system (RAAS) is part of a
complex feedback circuit that functions in homeostasis
The mammalian kidneys ability to
conserve water is a key terrestrial adaptation
Each adrenal gland actually
consist of two glands: adrenal medulla and adrenal cortex
negative feedback
control mechanism that reduces the stimulus
The "information receiving" section of a neuron is its _____.
dendrites
in what region of the nephron loop is water reabsorbed?
descending limb of loop of Henle
Which endocrine disorder is correctly matched with the malfunctioning gland?
diabetes insipidus and the posterior pituitary gland
The loop of Henle dips into the renal cortex. This is an important feature of osmoregulation in terrestrial vertebrates because___.
differential permeabilities of ascending & descending limbs of the loop of Henle are important in establishing an osmotic gradient.
The high osmolarity of the renal medulla is maintained by all of the following except
diffusion of salt from the descending limb of the loop of Henle.
excretory system functions
disposal of metabolic wastes; regulation of osmotic balance of blood
Connects the seminiferous tubules to the vas deferens Select one: a. scrotum b. collecting ducts c. urethra d. vas deferens e. epididymis
e. epididymis
glomerulus
each nephron has a single long tubules and a ball of capillaries called this
afferent arteriole
each nephron is supplied with blood by this; an offshoot of the renal artery that branches and forms capillaries of the glomerulus
Dilation of the afferent arteriole and glomerular capillaries and constriction of the efferent arteriole causes...
elevation of glomerular blood pressure
Osmoregulators expend
energy to control water uptake and loss in a hyper osmotic or hypo osmotic environment
macrophages
engulf foreign particles and cell debris
Negative feedback is a method of homeostatic control that _____.
ensures that conditions in an organism do not vary too much above or below their set points
renin
enzyme secreted by juxtaglomerular cells
Which of these extracellular signal molecules could diffuse through a plasma membrane and bind to an intracellular receptor?
estrogen
Which of these extracellular signal molecules could diffuse through a plasma membrane and bind to an intracellular receptor? estrogen epinephrine cellulose oxytocin starch
estrogen
If there is no fertilization, degeneration of the corpus luteum results in a drop in _____, which results in the sloughing off of the uterus's endometrium.
estrogen and progesterone
After ovulation, high levels of _____ inhibit _____ secretion.
estrogen and progesterone ... FSH and LH
To maintain homeostasis freshwater fish must___.
excrete large quantities of water
Neurotransmitters are released from axon terminals via
exocytosis
The movement of substances out of the glomerulus and into Bowman's capsule is referred to as _____.
filtration
Portal blood vessels connect two capillary beds found in the Select one: a. hypothalamus and anterior pituitary. b. anterior pituitary and adrenal gland. c. posterior pituitary and thyroid gland. d. hypothalamus and thalamus. e. anterior pituitary and posterior pituitary
a. hypothalamus and anterior pituitary.
Endocrine Singals
act on distant cells and are carried by blood or body fluids. Endocrine signals are, by definition, hormones. Cells that produce endocrine signals may be organized into discrete organs called glands, or they may be interspersed.
The relationship between the insect hormones ecdysteroid and PTTH is an example of
an interaction of the endocrine and nervous systems.
Which hormone(s) is(are) directly responsible for triggering the development of the secondary sex characteristics of males, such as beard growth?
androgens
Pheromones a
are signals that one individual releases into the environment that acts on a different individual of the same species. For example, pheromones function in some species in attracting mates. We do not consider them further.
skeletal muscle
attached to bones by tendons, voluntary, striated
Polypeptides can have which of the following types of effects?
autocrine, paracrine, and endocrine
anatomy
biological form
physiology
biological function
Bowman's capsule
blind end of the tubule forms a cup-shaped swelling called this; surrounds the glomerulus; filtrate is formed when blood pressure forces fluid from the blood in the glomerulus into the lumen of this
Urine is hypersomotic to
body fluids
human homeostasis
body temperature of 37 degrees C, blood pH within 0.1 unit of 7.4, blood glucose concentration 70-110 mg per 100 mL of blood
immune and lymphatic system components
bone marrow, lymph nodes, thymus, spleen, lymph vessels, white blood cells
Nitric oxide and epinephrine
both function as neurotransmitters.
nervous system components
brain, spinal cord, nerves, sensory organs
Seedless plants include _____.
bryophytes, lycophytes, ferns, whisk ferns, and horsetails
Parathyroid hormone (PTH) is released
by the parathyroid glands
The adrenal glands are
adjacent to the kidneys
albuminuria
can be caused by damage to the filtration membranes
The basic functional unit in the kidney is the...
nephron
vasocontriction
reduces blood flow and heat transfer by decreasing the diameter of superficial vessels
osmoreceptors stimulate [...] when firing?
magnocellular cells in hypothalamus to signal release of ADH from pituitary
BUN test
measure of blood nitrogen resulting from the catabolism and deamination of amino acids
Which of the following represents the correct sequence of events for sexual reproduction?
meiosis gametes zygote mitosis embryo
Aldosterone is an example of what class of hormones?
mineralcorticoids
proximal convoluted tubule
site of obligatory water reabsorption
The mesoderm gives rise to ___
skeletal and muscular systems
As filtrate moves down the loop of Henle, the surrounding interstitial fluid becomes _____ concentrated than the filtrate, so _____ leaves the filtrate.
more ... water
Under the influence of antidiuretic hormone (ADH), _____ is produced
more concentrated urine
Under the influence of antidiuretic hormone (ADH), _____ is produced.
more concentrated urine
Endocrine signaling is
one of the ways that information is transmitted between animal cells
Salamander and insect populations consisting only of genetically identical females lack males because _____
sperm do not fuse with eggs during reproduction, but the eggs develop into embryos anyway
In alternation of generations, what is the diploid stage of a plant that follows fertilization called?
sporophyte
In contrast to bryophytes, in vascular plants the dominant stage of the life cycle is the _____.
sporophyte
oxytocin
stimulates contraction of uterus and mammary gland cells
aldosterone
stimulates principal cells to secrete more K+ into tubular fluid and absorb more Na+ and Cl- into tubular fluid
DES is called an "endocrine disrupting chemical" because it structurally resembles, and interferes with, the endocrine secretions of the A) pancreatic islet cells.
ovaries.
atrial natriuretic peptide (ANP)
stretching of atria of heart stimulates secretion of this hormone
Increased ADH secretion is likely after
sweating-induced dehydration increases plasma osmolarity.
Preparation for the fight-or-flight response includes activation of the ________ nervous system.
sympathetic
Blood supply to the proximal and distal convoluted tubules of the nephron is provided by the...
peritubular capillaries
Removing which of the following glands would have the most wide-reaching effect on bodily functions of an adult human?
pituitary gland
endocrine system components
pituitary, thyroid, pancreas, adrenal, other hormone secreting glands
compared to concentration of Na in plasma and urine of a normal person, Na in plasma and urine of a pt with inappropriate increased ADH secretion will be [above/below]
plasma Na: below normal Urine Na: above normal
The surface on a neuron that discharges the contents of synaptic vesicles is the
presynaptic membrane.
A toxin that binds specifically to voltage-gated sodium channels in axons would be expected to
prevent the depolarization phase of the action potential.
what is the function of ADH
prevents elimination of water (antidiuretic) to correct for high osmolality
An injury to the occipital lobe will likely impair the function of the
primary visual cortex.
which cells express aldosterone receptors?
principle cells of collecting tubule
vasopressin/ADH
promotes retention of water by kidneys; influences social behavior and bonding
The primary site of nutrient reabsorption in the nephron is the...
proximal convoluted tubule
Under normal circumstances virtually all the glucose, amino acids, and other nutrients are reabsorbed before the filtrate leaves the...
proximal convoluted tubule
Na+ symporters
reabsorb Na+ together with a variety of other solutes
nervous tissue
receipt, processing, transmission of information
ectothermic
gain most of their heat from external sources; amphibians, many fish, nonavian reptiles, most invertebrates
what is the network of capillaries in the Bowman's capsule?
glomerulus
Unlike an earthworm's metanephridia, a mammalian nephron
receives filtrate from blood instead of coelomic fluid.
Unlike an earthworm's metanephridia, a mammalian nephron
receives filtrate from the blood instead of coelomic fluid.
organ systems
groups of organs that work together
vasa recta
hair pin shaped capillaries that serve the renal medulla and surround the loop of Henle
circulatory system components
heart, blood vessels, blood
Sexual reproduction includes a reproductive pattern called _____.
hermaphroditism
osmoregulation
homeostasis requires this; the process by which animals control solute concentration in the interstitial fluid and balance water gain and loss
If there is fertilization, secretion of _____ by the early embryo maintains the corpus luteum.
human chorionic gonadotropin
angiotensin II
reduces glomerular filtration rate; increases blood volume and pressure
Anterior pituitary
regulated by hormones released into portal blood vessels, synthesizes and releases PRL, synthesizes and releases TSH
ADH
regulates facultative water reabsorption by increasing the water permeability of principal ells in the distal convoluted tubules and collecting ducts.
Injury to just the hypothalamus would most likely disrupt _________
regulation of body temperature
Hormones are assembled into
regulatory pathways
The _____ are the major blood vessels transporting blood to the kidneys.
renal arteries
The three concentric layers of connective tissue that protect and anchor the kidneys are the...
renal capsule, adipose capsule, renal fascia
what is the cortical tissue located between the renal pyramids?
renal columns
The filtration of plasma that generates approximately 180 liters/day of filtrate occurs in the...
renal corpuscle
What is the correct sequence of flow through the nephron?
renal corpuslce>proximal tubule>loop of Henle>distal tubule>collecting duct
Oxytocin and antidiuretic hormone are synthesized in the
hypothalamus.
Freshwater fishes conserve
salt in their distal tubules and excrete large volumes of dilute urine
Osmoregulatory mechanisms of freshwater fish include
salt uptake in gills and water excretion in urine.
The filtrate produced in Bowman's capsule contains
salts, glucose, amino acids, vitamins, nitrogenous wastes, and other small molecules
Which of the following correctly traces the path of sperm from their site of production to their exit from a man's body?
seminiferous tubule → epididymis → vas deferens → urethra
Which of the following is not properly paired?
seminiferous tubule--cervix
The thermostat is a ____ that detects the stimulus and triggers a response
sensor
signal transduction
series of changes in cellular proteins that converts the extracellular signal to a specific intracellular response
This heating system maintains room temperature at or near a particular value, known as the
set point
atrial natriuretic peptide (ANP)
increases excretion of Na+ in urine (natriuresis); increases urine output (diuresis) and thus decreases blood volume
After drinking alcoholic beverages, increased urine excretion is the result of ___.
inhibited secretion of antidiuretic hormone (ADH)
Autocrine
signals act on the same cells that release them
Anterior Pituitary
-Regulated by hormones released into portal blood vessels -Synthesizes and releases both TSH and PRL
c Level: 1
17. Receptors sensitive to changes in the osmolality of extracellular fluid are the A) baroreceptors. B) chemoreceptors. C) osmoreceptors. D) pressoreceptors. E) proprioreceptors.
b Level: 1
18. Renin is released by the A) lungs. B) kidney. C) spleen. D) liver. E) pancreas.
a Level: 2
28. Atrial natriuretic hormone increases A) urine volume. B) ADH secretion. C) aldosterone secretion. D) the reabsorption of sodium ions. E) blood volume.
percent of filtrate that becomes urine?
< 1%
Increases water reabsorption
ADH secretion, dehydration due to inadequate water intake, sweating, eating salty food
Which lung structure is a tiny sac that functions as an interface between air and blood?
Alveolus.
Each person makes more than 1 million different B cell antigen receptors and more than 10 million different T cell antigen receptors. How is such diversity in antigen receptors generated?
By combining variable elements, the immune system assembles many different receptors from a much smaller collection of parts.
parathyroid hormone and vitamin D levels.
Calcium balance is influenced by ADH and parathyroid hormone levels. ADH and aldosterone levels. parathyroid hormone and vitamin D levels. aldosterone and parathyroid hormone levels.
ADH makes the _____ permeable to water?
Collecting duct
) Spermatogonia are ______. A primary spermatocyte is ______.
Diploid; diploid
H+ secretion increases; bicarbonate reabsorption increases
In renal compensation of acidosis, H+ secretion decreases; bicarbonate excretion increases. H+ secretion decreases; bicarbonate reabsorption increases. H+ secretion increases; bicarbonate reabsorption increases. H+ secretion increases; bicarbonate excretion increases.
In the male testis,___ causes Leydig cells to produce __
LH, testosteron
Select the correct statement contrasting gametophytes and sporophytes.
Sporophytes are diploid, whereas gametophytes are haploid.
Which event occurs first during diastole?
The atria and ventricles are relaxed, and blood flows into the atria.
Select the correct statement describing the osmolarity of mammalian urine.
The osmolarity of mammalian urine may vary over time.
urinary bladder
the 2 ureters drain into this common sac; during urination, urine is expelled from here
The cerebrospinal fluid is
a filtrate of the blood.
Which of the following results in long-term immunity?
the administration of the chicken pox vaccine
Fight-or-flight reactions include activation of
the adrenal medulla, leading to increased secretion of epinephrine
The amount of nitrogenous waste is coupled to
the animal's energy budget
Prolactin-releasing hormone from the hypothalamus stimulates
the anterior pituitary to secrete prolactin (PRL)
Freshwater fish excrete nitrogenous wastes as _____.
ammonia
Viruses and bacteria in body fluids are attacked by __
antibodies from B cells
Receptors for non steroid hormones are located in
association with a cell's plasma membrane
Does not increase water or Na+ reabsorption
diabetes insipidus, alcohol consumption, caffeine consumption
Osmoregulators must
expend energy to maintain osmotic gradients
loos connective
holds skin and other organs in place
renal calculi
insoluble stones of crystallized salts
circulatory system functions
internal distribution of materials
The juxtamedullary nephron is
key to water conservation in terrestrial animals
The primary site of regulating water, sodium, and potassium ion loss in the nephron is the...
loop of Henle and collecting duct
homeostasis
steady state
adipose tissue
stores fat
nephron
the functional unit of the kidney
Hormones that promote homeostasis
usually operate as part of a negative feedback system
nephrons
weave back and forth across the renal medulla and cortex; functional units
When the beta cells of the pancreas release insulin into the blood,
the skeletal muscles and the adipose cells take up glucose at a faster rate.
When a steroid hormone and a peptide hormone exert similar effects on a population of target cells, then
the steroid hormones affect the synthesis of effector proteins, whereas peptide hormones activate effector proteins already present in the cell.
The two solute model explaining urine production in the nephron states that
the transport epithelium in the ascending loop of Henle is relatively impermeable to water
The way that signals are transmitted between animal cells are classified by two criteria
the type of secreting cell, the route taken by the signal in reaching its target
An epitope associates with which part of an antibody?
the variable regions of a heavy chain and light chain combined
what happens when osmolality is increased even further beyond narrow range?
thirst increases water retention
A tropic hormone from the anterior pituitary gland regulates the secretion of
thyroxine.
The higher level of metabolic activity typical of nonhibernating temperate mammals during the winter months is due to increased secretion of
thyroxine.
The thick segments in the loop of Henle contain...
transport mechanisms that pump materials out of the filtrate
Contraction of the muscular bladder forces the urine out of the body through the...
urethra
Insects, land snails, and many reptiles including birds mainly excrete
uric acid
What nitrogenous waste has the greatest number of nitrogen atoms?
uric acid
hematuria
usually indicates a pathological condition
A fertilized egg usually implants itself and develops in the _____.
uterus
A clinical condition known as diabetes insipidus results in the production of large volumes of dilute urine. Which of the following is consistent with this condition?
very low production of ADH
In an animal that switches between sexual and asexual reproduction, when is sexual reproduction more likely to occur? ↓
when conditions for survival are unfavorable
how is cortisone reactivated and where?
when cortisone is transported to a glucocorticoid target cell, 11bHSD1 enzyme can reactivate it back to cortisol so it can bind to glucocorticoid receptors
when are ADH levels rapidly increased
when osmolality increases beyond narrow range of 280-285 mOsm/kg
In hormone systems, when does feedback inhibition occur?
when the presence of a hormone inhibits its release
vasodilation
widening of superficial blood vessels
This way the heating system maintains a stable room temperature is similar to the way an animal's body controls many aspects of its internal environment. The maintenance of a relatively constant internal environment is know as ______.
Homeostasis.
What makes up total body water?
ICF (66%) and ECF (33%)
The cell establishes high [...] in ICF and high [...] in ECF
ICF= K ECF= Na
glycogen synthesis.
Increased insulin secretion immediately following a meal will result in increased fat catabolism. glycogenolysis. gluconeogenesis. glycogen synthesis.
increases thirst.
Increased osmolality of the ECF increases thirst. inhibits ADH. increases renin secretion. increases aldosterone secretion.
increased urine output.
Increased secretion of atrial natriuretic hormone results in increased thirst. increased urine output. increased blood pressure. increased osmolality of the extracellular fluid.
After drinking alcoholic beverages, increased urine excretion is the result of ______.
Inhibited secretion of Vasopressin.
Adrenal medulla
(inner portion) secreted in response to stress-activated impulses from the nervous system, secretes epinephrine and norepinephrine
Main Energy Yielding Foods
- Carbohydrates and fats: Reservoirs of electrons associated with hydrogen; only the barrier of activation energy holds back the flood of electrons to a lower energy state
Infection-Fighting Complement System
- Consists of roughly 30 proteins in blood plasma - They circulate in an inactive state - Activated by substances on the surface of many microbes - Activation results in a cascade of biochemical reactions that can lead to lysis of invading cells - Also functions in the inflammatory response and in the adaptive defenses
Macrophages
- Larger phagocytic cells - Some migrate throughout the body while others reside permanently in organs and tissues where they are likely to encounter pathogens (i.e. located in spleen) - Some macrophages also reside lymph nodes, where they engulf pathogens that have flowed from the interstitial fluid into the lymph
Two Main Types of Phagocytic Cells in the Mammalian Body
- Neutrophils - Macrophages - There are also dendritic cells and eosinophils present - Natural killer cells have a role in innate immunity (but these are lymphocytes)
Structure of Chlorophyll Molecules in Chloroplasts of Plants
- Porphyrin ring: Light-absorbing "head" of molecule; note the magnesium atom at center (methyl group in chlorophyll a and an aldehyde CHO in chlorophyll b) - Hydrocarbon tail: Interacts with hydrophobic regions of proteins inside thylakoid membranes of chloroplasts
Blood Groups
- Red blood cells are designated as type A if they have the type A carbohydrate on their surface - The type B carbohydrate is found on type B red cells - Both A and B carbohydrates are found on type AB red blood cells and neither carbohydrate is found on type O red blood cells
What Type of Plant Would Gain from Increasing CO2 Levels
- Rising CO2 levels should benefit C3 plants by lowering the amount of photorespiration, but rising temperatures increase photorespiration - C4 plants could be largely unaffected by increasing CO2 levels or temperature
Anaerobic Respiration (general)
- Some prokaryotes use substances other than oxygen as reactants that harvests chemical energy without oxygen because they live in environments without oxygen - Do not use oxygen as a final electron acceptor at the end of the transport chain - Some "sulfate-reducing" marine bacteria use the sulfate ion at the end of their respiratory chain (H2S is produced as a by product rather than water) - Transfers electrons from NADH to pyruvate at the end of glycolysis
Cell-Mediated Immune Response
- Specialized T cells (cytotoxic T cells) destroy infected host cells - Includes a primary and secondary immune response (memory cells enable secondary immune response)
Pigments
- Substances that absorb visible light - If a pigment is illuminated with white light, the color we see is the color most reflected (or transmitted) by the pigment - See green when looking at a leaf because chlorophyll absorbs violet-blue and red light while transmitting and reflecting green light
Energy Flow and Chemical Recycling in Ecosystems
- Sunlight and exits as heat - Chemical elements essential to life are recycled
Proliferation/Clonal Selection of T Cell
- T cells also undergo clonal selection, generating memory T cells and effector T cells (helper T cells and cytotoxic T cells)
Aerobic Respiration (general)
- The most prevalent and efficient catabolic pathway - Oxygen is consumed as a reactant along with the organic fuel - Cells of most eukaryotic and many prokaryotic organisms can carry out aerobic respiration - Carbohydrates, fats, and proteins can all be processed and consumed as fuel--the steps of cellular respiration track the degradation of Glucose because it is the fuel that cells most often use
Primary Immune Response
- The production of effector cells from a clone of lymphocytes during the first exposure to an antigen - Primary response peaks about 10-17 days after the initial exposure (During this time, selected B cells and T cells give rise to their effector forms)
Hypothalamus
-Integrates nervous and endocrine systems. -Synthesizes Oxytocin and ADH -Synthesizes some hormones that are released into blood vessels bound for another gland
Neurotransmitters affect postsynaptic cells by
-causing molecular changes in the cells. -altering the permeability of the cells. -affecting ion-channel proteins. -initiating signal transduction pathways in the cells.
After traveling through the nephron and the collecting duct, urine is more concentrated than other body fluids and excretes urea and other wastes with a minimal loss of water. The ability of mammalian kidneys to conserve water in this way is a key terrestrial adaptation.
...
Endocrines (e.g., classical hormones) Neuroendocrines (e.g., classical hormones, but released by nerve cells)
...
Terrestrial animals have to drink quantities of water or obtain water from their food to survive.
...
An animal may be a regulator for one environmental variable...
...but a conformer for another
loop of Henle
1 of the 3 main regions of the nephron; a hair pin turn with a descending limb and an ascending limb
Steps of inhalation.
1) Diaphragm and rib muscles contract. 2) Lung volume increases. 3) Air moves into nose and down trachea, bronchi, and bronchioles. 4) Air enters alveoli. 5) O2 diffuses into blood; CO2 diffuses into alveoli.
Steps of exhalation.
1) Diaphragm and rib muscles relax. 2) Lung volume decreases. 3) Air moves out of alveoli. 4) Air moves up bronchioles, bronchi, and trachea. 5) Air leaves nose or mouth.
Mast Cells, IgE, and the Allergic Response
1) IgE antibodies produced in response to initial exposure to an allergen bind to receptors on mast cells 2) On subsequent exposure to the same allergen, IgE molecules attached to a mast cell recognize and bind the allergen 3) Cross-linking of adjacent IgE molecules triggers release of histamine and other chemicals, leading to allergy symptoms
Phagocytosis
1) Pseudopodia surround pathogens 2) Pathogens are engulfed by endocytosis 3) Vacuole forms, enclosing pathogens 4) Vacuole and lysosome fuse 5) Toxic compounds and lysosomal enzymes destroy pathogens 6) Debris from pathogens is released by exocytosis
Aldosterone secretion is stimulated by what physiological signals
1. decrease in volume 2. decrease in Na signals detected by kidney
what are the 2 actions of V2 receptors upon ADH binding?
1. expression of aquaporin 2 receptors 2. activates mechanism that moves vesicles with aquaporin2 to fuse with apical membrane
a Level: 2
10. One difference between the plasma and interstitial fluid is that the plasma has significantly more _____ than interstitial fluid. A) protein B) bicarbonate C) chloride D) water volume E) hydrogen ions
a Level: 1
13. The cation that plays a major role in determining the osmotic pressure of the plasma is A) sodium. B) potassium. C) chloride. D) phosphate. E) hydrogen ion.
c Level: 2
33. Which of the following statements concerning potassium ions is false? A) An increase in the extracellular potassium ion concentration leads to depolarization. B) Potassium ions are secreted into the nephron by the distal convoluted tubule. C) When aldosterone levels are high, potassium secretion is low. D) Aldosterone secretion is stimulated by high blood levels of potassium ions. E) none of the above are false
d Level: 1
34. Potassium levels in the body are regulated by A) ADH. B) PTH. C) calcitonin. D) aldosterone. E) insulin.
Percent increase in blood flow due to stimulation? (25200/5040)
500%
a Level: 2
76. When normal buffer mechanisms are overwhelmed by excessive numbers of hydrogen ions, which of the following will result? A) acidosis B) alkalosis C) neither of these
b Level: 2
78. Ingesting large amounts of sodium bicarbonate can lead to A) metabolic acidosis. B) metabolic alkalosis. C) respiratory acidosis. D) respiratory alkalosis. E) none of the above
24) Oxytocin and ADH are produced by the ________ and stored in the ________. A) hypothalamus; neurohypophysis B) adenohypophysis; kidneys C) anterior pituitary; thyroid D) adrenal cortex; adrenal medulla E) posterior pituitary; anterior pituitary
A
37) Which endocrine disorder is correctly matched with the malfunctioning gland? A) diabetes insipidus and the posterior pituitary gland B) giantism and the posterior pituitary gland C) goiter and the adrenal medulla D) diabetes mellitus and the parathyroid glands E) dwarfism and the adrenal cortex
A
93) Which of the following is true about calcium homeostasis? A) Parathyroid hormone is the single most important regulator of calcium levels in the blood. B) Increased calcitonin levels will cause increased blood calcium levels. C) Parathyroid hormone causes an increase in osteoblast activity. D) High calcium levels cause bone resorption.
A
In contrast to acclimatization, adaption involves _____.
A change in allele frequency over many generations.
Which of the following is most likely to be found in a terrestrial animal with high activity rates?
A four-chambered heart, which helps create strong blood pressure and efficient oxygenation.
increase the uptake of glucose by its target tissues.
A function of insulin is to increase the uptake of glucose by its target tissues. decrease the uptake of amino acids by its target tissues. increase glycogen breakdown in the liver and skeletal muscle. increase breakdown of fats.
Which of the following statements best describes the actions of the hormone ADH on the nephron?
ADH causes the collecting duct to increase water reabsorption by the surrounding tissue under conditions of dehydration.
Which of the following characterizes parthenogenesis?
An egg develops without being fertilized.
_____ are the main male hormones.
Androgens
____are the main male hormones
Androgens
_____ are the main male hormones.
Androgens (testosterone)
Where and when does osmolarity of the filtrate increase?
As the filtrate moves down the descending limb of the loop of Henle
67) ADH ________. A) promotes dehydration B) is inhibited by alcohol C) is produced in the adenohypophysis D) increases urine production
B
Which of the following levels of analysis is not typically used to measure biodiversity?
Behavior.
Which one of the following descriptions of the part of a mammalian kidney is NOT correct?
Bowman's capsule—a ball of capillaries associated with the end of a long tubule
15) Frequently, very few molecules of a hormone are required to affect changes in a target cell. This is because A) hormones are lipid-soluble and readily penetrate the membranes of the target cell. B) hormones are large molecules that remain in circulation for months and can repeatedly stimulate the same cell. C) the mechanism of hormonal action involves an enzyme cascade that amplifies the response to a hormone. D) the mechanism of hormonal action involves the rapid replication of the hormone within the target cell. E) the mechanism of hormonal action involves memory cells that have had prior contact with the hormone.
C
) The pathway for cortisol secretion is the following. ______ in the hypothalamus causes ______ to be released by the pituitary, which causes cortisol to be released by the _____.
Corticotropin-releasing hormone (CRH); adrenocorticotropic hormone (ACTH); adrenal glands
36) A tropic hormone from the anterior pituitary gland regulates the secretion of A) parathyroid hormone. B) calcitonin. C) epinephrine. D) thyroxine. E) glucagon.
D
39) Fight-or-flight reactions include activation of A) the parathyroid glands, leading to increased metabolic rate. B) the thyroid gland, leading to an increase in the blood calcium concentration. C) the anterior pituitary gland, leading to cessation of gonadal function. D) the adrenal medulla, leading to increased secretion of epinephrine. E) the pancreas, leading to a reduction in the blood sugar concentration.
D
41) The body's reaction to PTH (parathyroid hormone), a reduction in plasma levels of calcium, can be opposed by A) thyroxine. B) epinephrine. C) growth hormone. D) calcitonin. E) glucagon.
D
thiazide diuretics
Diuretics that inhibit sodium ion reabsorption are called xanthines. osmotic diuretics. thiazide diuretics. carbonic anhydrase inhibitors
Select the correct statement describing the life cycle of angiosperms.
Double fertilization in the life cycle of seed plants results in the production of a diploid zygote and a triploid endosperm nucleus.
44) Which structure increases the reabsorption of Na+ when stimulated by aldosterone? A) loop of Henle B) collecting duct C) Bowman's capsule D) proximal tubule E) distal tubules
E) distal tubules
True or False? The pressure inside the human chest cavity is always positive, so the lungs stay relatively inflated even upon exhalation.
False. The lungs stay relatively inflated even upon exhalation because the pressure inside the chest cavity is always negative.
) Ovulation occurs at the end of the _____ phase and the beginning of the _____ phase of the human menstrual cycle. As the luteal phase of the menstrual cycle progresses to its end, the corpus luteum _____.
Follicular phase; luteal phase; degenerates
pressure gradient.
Formation of filtrate depends on a pressure gradient. concentration gradient. volume gradient. temperature gradient.
What is the correct response if the blood sugar drops for a person with type 1 diabetes mellitus?
Give the person a candy bar. The high concentration of sugar will help boost their glucose level.
correct
Glomerular filtration rate is directly related to the pressures that determine net filtration pressure.
B. zona fasciculata, influence protein and fat metabolism, and promote vasoconstriction
Glucocorticoids are produced in the A. zona glomerulosa and regulate the concentration of extracellular electrolytes B. zona fasciculata, influence protein and fat metabolism, and promote vasoconstriction C. zona glomerulosa and supplement sex hormones from the ovaries D. zona fasciculata, regulate concentration of extracellular electrolytes, and influence carbohydrate metabolism
) Pregnancy testing kits detect the presence of (or a very large increase in)
Human chorionic gonadotropin (hCG).
50 mmHg
If the following hypothetical conditions exist in the nephron, calculate the net filtration pressure. glomerular capillary pressure = 80 mmHg blood colloid osmotic pressure = 20 mmHg capsular colloid pressure = 10 mmHg 110 mmHg 90 mmHg 50 mmHg 30 mmHg
Select the example that accurately illustrates this statement: "The endocrine and nervous systems act together to regulate an animal's physiology."
In response to stress, neurosecretory cells in the adrenal medulla release epinephrine and norepinephrine, which mediate various fight-or-flight responses.
) Viviparous animals are animals
In which embryonic development takes place inside the mother's body.
ADH levels decrease
In which of the following situations does one see large volumes of dilute urine produced? ADH levels decrease renin levels increase aldosterone levels increase parathyroid hormone levels decrease
A decrease from pH 7.4 to pH 7.2 causes hemoglobin to ____.
Increase its binding of H+.
The heater turns on, and the temperature in the room ____ until it returns to the original setting.
Increases.
Melatonin
Jet lag occurs when a person moves rapidly from one time zone to another, causing conflict between the body's biological rhythm and the new cycle of light and dark. Some scientists suspect that jet lag may result from disruption of a daily hormone cycle known as _____.
Which one of the following is extremely important for water conservation in mammals?
Juxtamedullary nephron
The distal tubule regulates the
K+ and NaCl concentrations of body fluids, the controlled movement of ions contributes to pH regulation
B. characterized by muscular weakness, tachycardia, and dizziness
Lower than normal blood concentration of sodium is A. called hypernatremia B. characterized by muscular weakness, tachycardia, and dizziness C. characterized by thirst, restlessness, agitation, and coma D. due to the fact that most people do not consume enough sodium
Which hormone spikes midway through the menstrual cycle and triggers ovulation?
Luteinizing hormone (LH).
A product of the anterior pituitary gland that causes color changes in its target cells is
MSH.
Where is ADH synthesized?
Magnocellular cells of hypothalamus
osmoreceptors.
Receptors sensitive to changes in the osmolality of extracellular fluid are the baroreceptors. chemoreceptors. osmoreceptors. pressoreceptors.
C. hypothalamus
The ____________ is the major integrating link between the nervous and endocrine systems. A. thyroid gland B. pancreas C. hypothalamus D. primary somatosensory cortex
a high medullary concentration gradient.
The ability of the kidney to concentrate urine depends on proximal tubule reabsorption. a high medullary concentration gradient. osmosis. rapid removal of filtrate.
D. hypothalamus of the brain
The cell bodies of the axons of the posterior pituitary gland are actually located in the A. infundibulum B. anterior pituitary gland C. cerebral cortex D. hypothalamus of the brain
You just received a freshwater aquarium as a gift and decide to add more fish. When you get to the pet store, you find that the most beautiful fish are saltwater animals, but you decide to buy them anyway. What will happen when you put your expensive saltwater fish in you freshwater aquarium?
The cells of the fish will take up too much water and the fish will die
B. PTH
The concentration of calcium ions and phosphates in the blood is regulated by A. thyroid hormone B. PTH C. growth hormone
Why do the circulatory system of land vertebrates have separate circuits to the lungs and to the rest of the body?
The large decrease in blood pressure as blood moves through the lungs may prevent efficient circulation through the rest of the body.
peritubular capillary.
The vasa recta is a specialized portion of the glomulerus. afferent arteriole. efferent arteriole. peritubular capillary
Which event of the cardiac cycle occurs when systolic blood pressure is measured?
The ventricles contract, carrying blood into the aorta, and blood flows into the relaxed atria.
both a and c
The visceral layer of Bowman's capsule is part of the filtration membrane. is called endothelium. contains podocytes. both a and b both a and c
What is unique about transport epithelial cells in the ascending loop of Henle in humans?
Their membranes are impermeable to water
Which of the following statements about lipid-soluble hormones is true? They act by producing second messengers. They bind to receptors on the plasma membrane. They act by affecting the transcription of genes. They bind to DNA as soon as they enter a cell.
They act by affecting the transcription of genes
Why do some species employ both mitosis and meiosis, whereas other species use only mitosis?
They need both if they are producing animal gametes.
An elderly man arrives at the hospital severely dehydrated. The physicians find that there is glucose in his urine and that his blood glucose does not decline much upon administration of an insulin shot. What is he likely to be suffering from?
Type 2 diabetes mellitus.
This disorder typically arises prior to puberty and is generally treated by injections of the hormone missing from the affected individual's bloodstream.
Type I diabetes mellitus; Type I diabetes mellitus is also known as childhood-onset diabetes. Hypoactivity of the pancreas' secretion of insulin disturbs the homeostasis of glucose levels in the blood, and these are corrected by administering injections of insulin.
collecting duct.
Urine drains from the nephron into the calyces through the loop of Henle. collecting duct. distal convoluted tubule. proximal convoluted tubule
decreasing renin secretion.
When macula densa cells experience increased Na+ concentration in the filtrate, they respond by increasing afferent arteriole constriction. decreasing urine production. decreasing renin secretion. increasing aldosterone secretion
the excess remains in the filtrate.
When the tubular maximum for a substance is exceeded, more of the substance is reabsorbed. more of the substance is actively secreted. less of the substance is filtered in the renal corpuscle. the excess remains in the filtrate.
Calcitonin
Which hormone opposes the action of parathyroid hormone?
C. cortisol
Which of the following is classified as a glucocorticoid? A. vasopressin B. aldosterone C. cortisol D. epinephrine
NaCl buffer system
Which of the following is not a buffer system of the body? bicarbonate buffer system phosphate buffer system protein buffer system NaCl buffer system
) Chromosome abnormalities are more likely in offspring of older ______. Deleterious mutations are more likely in offspring of older ______.
Women; men
Diabetes mellitus is caused by
a deficiency of insulin or a decreased response to insulin in target tissues
) During mammalian labor and delivery, the contraction of uterine muscles is enhanced by oxytocin. This is an example of
a hormone that is involved in a positive feedback loop.
During mammalian labor and delivery, the contraction of uterine muscles is enhanced by oxytocin. This is an example of Select one: a. signal transduction immediately changing gene expression in its target cells. b. the key role of the anterior pituitary gland in regulating uterine contraction. c. a negative feedback system d. a hormone that acts in an antagonistic way with another hormone e. a hormone that is involved in a positive feedback loop.
a hormone that is involved in a positive feedback loop.
Which of the following animals generally has the lowest volume of urine production?
a marine bony fish
Natural selection should favor the highest proportion of juxtamedullary nephrons in which of the following species?
a mouse species living in the desert
Which of the following best describes the neuroendocrine-to-endocrine pathway of hormone action?
a neural organ that produces hormones regulates another gland through the release of hormones into the circulation that travel to the effected gland
The interrelationships between the endocrine and the nervous systems are especially apparent in
a neurosecretory cell in the hypothalamus.
Through a microscope, you can see a cell plate beginning to develop across the middle of a cell and nuclei re-forming on either side of the cell plate. This cell is most likely
a plant cell in the process of cytokinesis.
Basophils
a type of WBC that promotes inflammation and participates in allergic responses. Normally circulates in the blood simialr to mast cells.
intercalated cells
can secrete H+ against a concentration gradient
blood
consists of cells and cell fragments suspended in plasma
response
control center generates output that triggers this after receiving a signal from the sensor; helps return variable to set point
CAD
coronary artery disease
CHD
coronary heart disease
Which of the following criteria have to be met for a species to qualify as invasive? 1) Endemic to the area, spreads slowly, and displaces native species 2) Introduced to a new area, spreads rapidly, and displaces native species 3) Introduced to a new area, spreads rapidly, and displaces other invasive species 4) endemic to the area, spreads rapidly, and displaces foreign species.
Introduced to a new area, spreads rapidly, and displaces native species.
Hyperthyroidism
excessive production of thyroid hormone, can lead to high temperature, sweating, weight loss, irritability, and high blood pressure
The collecting duct carries
filtrate through the medulla to the renal pelvis
In the proximal tubule,
filtrate volume decreases but its osmolarity remains the same
The suprachiasmatic nuclei are found in the
hypothalamus
urea
in vertebrates, it is the product of a metabolic cycle that combines ammonia with carbon dioxide in the liver; very low toxicity
The hypothalamus
includes neurosecretory cells that terminate in the posterior pituitary.
A simple nervous system
includes sensory information, an integrating center, and effectors.
what signals stimulate ANP secretion
increase in blood volume increase in atrial stretch
Hormone cascade pathway typically
involve negative feedback
Prolactin stimulates mammary gland growth and development in mammals and regulates salt and water balance in freshwater fish. Many scientists think that this wide range of functions indicates that prolactin
is an evolutionarily conserved hormone.
What evolutionary development allowed plants to grow tall?
lignified vascular tissue
mineralocorticoids
promote reabsorption of Na+ and excretion of K+ in kidneys
neurons
receives nerve impulses from other neurons via its cell body and dendrites; transmit impulses to neurons, muscles, other cells via axons
fibroblasts
secrete fiber proteins
Meiosis II is similar to mitosis in that
sister chromatids separate during anaphase.
Spermatogenesis
the process of forming sperm
Birds, reptiles, and mammals are called "amniotes" because _____.
they have extra-embryonic membranes that develop an aqueous environment in which development occur
When urine leaves the kidney, it travels to the urinary bladder via the...
ureters
Urine leaving the kidneys travels along the following sequential pathway to the exterior:
ureters → urinary bladder → urethra
A human who has no access to fresh water but is forced to drink seawater instead will__.
will excrete more water molecules than taken in, because of the high load of ion ingestion.
Antigen
- Any substance that elicits a response from a B cell or T cell - In adaptive immunity, recognition occurs when a B cell or T cell binds to an antigen, such as a bacterial or viral protein, via a protein called an antigen receptor - Usually foreign - Typically large molecules (either proteins or polysaccharides) - Many antigens may protrude from the surface of foreign cells or viruses - Some antigens, such as toxins secreted by bacteria, are released into the extracellular fluid
PS I
- Chlorophyll a at the reaction-center complex of photosystem I is called P700 because it absorbs light of wavelength 700 nm best (far-red part of spectrum)
Photosystem
- Chlorophyll molecules are organized along with other small organic molecules and proteins into these complexes along the thylakoid membrane - Composed of a reaction-center complex surrounded by light harvesting complexes
Neutrophils
- Circulate in the blood - Attracted by signals from infected tissues and then engulf and destroy the infecting pathogens
Light-Harvesting Complex
- Consists of various pigment molecules (which may include chlorophyll a, chlorophyll b, and carotenoids) bound to proteins - Number and variety of pigment molecules enable a photosystem to harvest light over a larger surface area and a larger portion of the sprectrum - These complexes act as an antenna for the reaction-center complex - When a pigment molecule absorbs a photon, the energy is transferred from pigment molecule to pigment molecule until it is passed into the reaction-center complex
T Cells (general)
- Lymphocytes that migrate from the bone marrow to the thymus (an organ in the thoracic cavity above the heart) mature into T cells
B Cells (general)
- Lymphocytes that remain and mature in the bone marrow develop into B cells
Action Spectrum for Photosynthesis
- Profiles the relative effectiveness of different wavelengths of radiation in driving the process - Prepared by illuminating chloroplasts with light of different colors and then plotting wavelength against some measure of photosynthetic rate (i.e. CO2 consumption or O2 release) - Does not exactly match the absorption spectrum of chlorophyll a
The kidneys are paired organs that regulate water and electrolyte balance in terrestrial vertebrates.
...
The passive and active transport of NaCl and the passive transport of urea create an osmolarity gradient between the cortex and medulla of the kidney. As the filtrate moves through the nephron, water leaves the filtrate by osmosis. The loss of water results in urine that is highly concentrated. Antidiuretic hormone (ADH) also helps to regulate urine concentration by controlling NaCl transport and water permeability in the collecting duct.
...
Stages of Aerobic Cell Respiration
1)Glycolysis (substrate level phosphorylation) 2) Link Reaction (Oxidative Decarboxylation/Pyruvate Oxidation) 3) Citric Acid Cycle / Kreb's Cycle (substrate level phosphorylation) 4) Electron Transport Chain and chemiosmosis (oxidative phosphorylation)
Volume of blood moved per minute by a heart that has been stimulated by epinephrine. (heart stimulated by epinephrine, heart rate doubles and volume of blood moved per beat triples. 72 BOM, 70mL per beat)
30240mL
d Level: 2
31. Chloride ions A) are cations. B) are found only inside cells. C) are part of the DNA molecule. D) are lost when vomiting. E) are not found in extracellular fluid.
a Level: 2
40. Which of the following is correctly matched? A) alkalosis - hypokalemia B) cell destruction - hypokalemia C) increased secretion of aldosterone - hyperkalemia D) overuse of diuretics - hyperkalemia E) acidosis - hypokalemia
b Level: 1
47. Stimulus for the secretion of parathyroid hormone is a decrease in serum A) potassium levels. B) calcium levels. C) calcitonin levels. D) phosphate levels. E) sodium levels.
c Level: 1
48. Parathyroid hormone effects the A) bones, heart, and blood. B) kidney, liver, and spleen. C) intestine, kidneys, and bone. D) liver, stomach, and small intestine. E) stomach, pancreas, and bone
Calculate the volume of blood moved per minute by a heart at rest. (Heart "at rest" beats at 72 BPM and moves 70 mL per beat)
5040mL
d Level: 2
51. Calcitonin A) promotes the absorption of calcium from the gastrointestinal tract. B) promotes osteoclast activity in the bones. C) reduces calcium excretion by the kidneys. D) reduces extracellular calcium ion levels. E) increases blood calcium levels.
a Level: 2
54. Angiotensin II increases blood volume by stimulating A) thirst. B) vasodilatation. C) water movement into the cells. D) renal excretion of sodium. E) ADH production.
d Level: 2
60. A person working in the hot sun loses the greatest amount of water from the A) lungs. B) urine. C) mouth. D) skin. E) GI tract.
Estimate total population size in a mark-recapture study in which 200 individuals were initially marked, and you recaptured 150 of which 50 were marked.
600.
a Level: 1
62. Which of the following substances releases hydrogen ions into a solution? A) acids B) bases C) salts D) glucose E) water
b Level: 2
69. Which of the following terms does not belong with the other three? A) acidosis B) pH increases C) H+ ion concentration increases D) carbonic acid levels increase E) pH decreases
25) The hypothalamus modulates hormone secretion by the anterior pituitary by means of A) peptide hormones. B) steroid hormones. C) electrical synapses. D) neurotransmitters. E) paracrine signals.
A
3) Which of the following is (are) true? A) Hormones regulate cellular functions, and negative feedback regulates hormone levels. B) The circulating level of a hormone is held constant through a series of positive feedback loops. C) Both lipid-soluble hormones and water-soluble hormones bind to intracellular protein receptors. D) Only A and D are true. E) A, B, and C are true.
A
The exhalation of air from human lungs is driven by _____.
A decrease in the volume of the thoracic cavity.
C. uncompensated respiratory
A patient whose blood pH is 7.5, whose concentration of HCO3- in arterial blood is 25 mEq/liter, and whose partial pressure of CO2 is 32 mm Hg in arterial blood is experiencing ________alkalosis? A. uncompensated metabolic B. compensated metabolic C. uncompensated respiratory D. compensated respiratory
46) In a laboratory experiment with three groups, one group of people drinks pure water, a second group drinks an equal amount of beer, and a third group drinks an equal amount of concentrated salt solution all during the same time period. Their urine production is monitored for several hours. At the end of the measurement period, which group will have produced the greatest volume of urine and which group the least? A) beer the most, salt solution the least B) salt solution the most, water the least C) water the most, beer the least D) beer the most, water the least E) There will be no significant difference between these groups.
A) beer the most, salt solution the least
24) Which part of the vertebrate nephron consists of capillaries? A) glomerulus B) loop of Henle C) distal tubule D) Bowman's capsule E) collecting duct
A) glomerulus
B. stimulates the adrenal cortex to secrete glucocorticoids
Adrenocorticotropic hormone A. promotes normal functioning of the adrenal medulla B. stimulates the adrenal cortex to secrete glucocorticoids C. promotes release of CRF from the hypothalamus D. stimulates the adrenal medulla to secrete mineralocorticoids
Order in energy requirements from least to greatest Ammonia Uric Acid Urea
Ammonia < Urea < Uric Acid
52) Melatonin is secreted by A) the hypothalamus during the day. B) the pineal gland during the night. C) the autonomic nervous system during the winter. D) the posterior pituitary gland during the day. E) the thyroid gland during cold seasons.
B
Which of the following is/are difference(s) between the fission of a bacterium and mitosis in human cells?
Bacteria are smaller and simpler than human cells. Duplicated bacterial chromosomes attach to the plasma membrane. Duplicated human chromosomes are attached to each other. Human chromosomes are larger and more complex. A bacterium has only one chromosome, human chromosomes are paired.
Which of the following terms includes all of the others? 1) biodiversity 2) ecosystem diversity 3) species richness 4) species diversity 5) genetic diversity
Biodiversity.
pathway of urine formation?
Bowman's capsule → glomerulus → proximal convoluted tubule → descending limb → loop of Henle → ascending limb → distal convoluted tubule → collecting duct → papillary duct → minor calyx → major calyx → renal pelvis → ureter → urinary bladder → urethra
what is the pathway of filtrate formation within nephron?
Bowman's capsule → glomerulus → proximal convoluted tubule → descending limb → loop of Henle → ascending limb → distal convoluted tubule → collecting duct/ system
46) A chemical signal that has both endocrine and neural roles is A) parathyroid hormone. B) calcitonin. C) epinephrine. D) acetylcholine. E) ecdysone.
C
94) Aldosterone ________. A) presence increases potassium concentration in the blood B) is secreted by the neurohypophysis C) functions to increase sodium reabsorption D) production is greatly influenced by ACTH
C
32) Which structure possesses specialized cells called podocytes? A) loop of Henle B) collecting duct C) Bowman's capsule D) proximal tubule E) glomerulus
C) Bowman's capsule
16) Which of the following is a nitrogenous waste that requires hardly any water for its excretion? A) amino acid B) urea C) uric acid D) ammonia E) nitrogen gas
C) uric acid
Select the correct statement about charophytes, a taxon of green algae.
Charophytes and land plants share four distinctive traits.
38) Which of the following processes of osmoregulation by the kidney is the least selective? A) salt pumping to control osmolarity B) H+ pumping to control pH C) reabsorption D) filtration E) secretion
D) filtration
33) Which structure is the first section of the nephron tubule into which the filtrate enters? A) loop of Henle B) collecting duct C) ureter D) proximal tubule E) glomerulus
D) proximal tubule
) LCFA-CoAs (long-chain fatty acid-CoAs) act in the brain to ______ food intake. They are not effective if you eat a ______ fat diet.
Decrease; high
increasing net filtration pressure.
Decreased blood colloid osmotic pressure affects renal function by increasing net filtration pressure. increasing capsular pressure. increasing glomerular capillary pressure. increasing blood pressure in the afferent arteriole.
55) After eating a carbohydrate-rich meal, the mammalian pancreas increases its secretion of A) ecdysone. B) glucagon. C) thyroxine. D) oxytocin. E) insulin.
E
68) The primary reason steroid hormones usually act slowly is that A) target cells tend to ignore steroid hormones in favor of nonsteroid hormones. B) they are produced at very low concentrations. C) they are too large to enter a cell and therefore must first bind to a plasma membrane receptor before having an effect on a cell. D) acting via a signal transduction pathway makes for slower responses than does directly interacting with a cell's DNA. E) they turn genes on or off and it takes time for gene products to build up or become depleted.
E
Which of these hormones are responsible for the "fight or flight" response to danger? insulin and glucagon thyroxine and calcitonin androgens and estrogens antidiuretic hormone (ADH) and oxytocin epinephrine and norepinephrine
E and NRE
15) What is the main nitrogenous waste excreted by birds? A) ammonia B) nitrate C) nitrite D) urea E) uric acid
E) uric acid
The figure shows how glucose homeostasis is maintained by two antagonistic hormones, insulin and glucagon. Select the correct statement about these hormones.
Each of these hormones operates in a simple endocrine pathway.
What is the role of recombinase in generating lymphocyte diversity?
Early in B cell development, recombinase links one light-chain V gene segment to one J gene segment.
Eicosanoid hormones are produced in A. the hypothalamus B. the ovaries and testes C. enteroendrocrine cells of the stomach and intestine D. all cells except red blood cells
Eicosanoid hormones are produced in A. the hypothalamus B. the ovaries and testes C. enteroendrocrine cells of the stomach and intestine Eicosanoid hormones are produced in A. the hypothalamus B. the ovaries and testes C. enteroendrocrine cells of the stomach and intestine D. all cells except red blood cells
C. diabetes mellitus
Either a deficiency of insulin production by the pancreas, or defects in insulin receptors on target cells, result in the disease A. myxedema B. cretinism C. diabetes mellitus D. diabetes insipidis
Which of these extracellular signal molecules could diffuse through a plasma membrane and bind to an intracellular receptor? estrogen epinephrine cellulose oxytocin starch
Estrogen
) At the time that a human egg is fertilized by a sperm (but before fusion of the egg nucleus with the sperm nucleus), the egg nucleus
Has completed meiosis I, but has not entered into meiosis II.
What is the fundamental difference between male and female vertebrates?
Males produce many, motile gametes and females produce few, stationary gametes
ATP hydrolysis directly powers the movement of
Na+ out of cells.
D. causes renal tubule cells to reabsorb calcium
Parathyroid hormone A. is released when blood calcium level rises B. stimulates osteoblasts and inhibits osteoclasts C. causes the cells of the nephron to reabsorb phosphate D. causes renal tubule cells to reabsorb calcium
Which hormone stimulates milk production?
Prolactin; Prolactin, secreted by the anterior pituitary, stimulates milk production by the mammary glands.
PAH
Renal blood flow per minute can be calculated if you know the clearance calculation for ____ as well as the person's hematocrit. ADH PAH inulin aldosterone
kidney.
Renin is released by the lungs. kidney. spleen. liver.
Which of the following develops the greatest pressure on the blood in the mammalian aorta? 1) Diastole of the right ventricle 2) Diastole of the right atrium 3) Diastole of the left atrium 4) Systole of the left ventricle 5) Systole of the left atrium
Systole of the left ventricle
) After production through spermatogenesis, human sperm are stored in
The epididymis.
In hormone production, how do the follicle and corpus luteum compare?
The follicle produces more estradiol than progesterone; the corpus luteum produces more progesterone than estradiol.
How is the production of hormones such as thyroxine and estrogen regulated?
The hypothalamus directs the anterior pituitary to produce hormones that then stimulate or inhibit the production of these hormones; The hypothalamus directs the anterior pituitary to produce hormones that regulate other hormones in a variety of endocrine organs, including the thyroid gland and ovaries.
) In mammalian species where the female frequently mates with more than one male,
The last male to mate is most likely to be the father of the offspring.
B. double
The metabolic rate of infants is about _______ as that of adults. A. the same B. double C. triple D. quadruple
The greatest difference in the concentration of respiratory gases is found in which of the following pairs of mammalian blood vessels?
The pulmonary vein and the jugular vein.
When the beta cells of the pancreas release insulin into the blood, _____.
The skeletal muscles and the adipose cells take up glucose at a faster rate.
E
The urethra is identified by the letter
all of the above
To calculate plasma clearance of any substance, it is necessary to know the quantity of urine produced per minute. concentration of the cleared substance in the urine. concentration of the cleared substance in the blood. all of the above
False. Only low concentrations of hormones are needed in the bloodstream to activate a signal transduction pathway, which works by producing second messengers inside the cell that amplify the hormonal signal.
True or false? For a signal transduction pathway to be activated, hormones must be present in the bloodstream at very high concentrations.
other ADH receptors include
V1 causes vasocontriction in liver, smooth muscle, vasculature, peripheral tissues (Gq) to increase blood pressure V3 causes corticotropin secretion from adenohypophysis (Gq)
osmosis.
Water reabsorption by the renal tubules uses active transport. cotransport. solvent drag. osmosis.
If you are under stress for a very long time,
You will have a decreased ability to terminate cortisol production after the stressful situation is relieved.
The body fluids of freshwater crustaceans generally have a lower osmolarity than the body fluids of their nearest marine crustacean relatives. Which of the following is a benefit of reduced osmolarity of body fluids in freshwater crustaceans?
a reduction in energy expenditures for osmoregulation
Glucose is removed from filtrate by _____.
active transportation
Blood arrives at the renal corpuscle by way of an...
afferent arteriole
what inhibits ADH secretion leading to a decrease in water retention
alcohol (diuretic) alpha blockers glucocorticoids
Increases both water and Na+ reabsorption
aldosterone release, blood loss, severe diarrhea
conformer
allows internal condition to change in accordance with external changes; bass
Which of the following characteristics of plants is ABSENT in their closest relatives, the charophyte algae?
alternation of generations
In a positive-feedback system where hormone A alters the amount of protein X
an increase in A always produces an increase in X.
describe the pathway of urine formation (gross anatomical structures)
aorta/arteries → kidney → ureter → urinary bladder → urethra
Receptors for nonsteroid hormones are located in _____.
association with a cell's plasma membrane
Choose the correct match of glial cell type and function.
astrocytes-metabolize neurotransmitters and modulate synaptic effectiveness
In a simple synapse, neurotransmitter chemicals are received by Select one: a. cell bodies. b. membranes on the dendrites c. ducts on the smooth endoplasmic reticulum d. membranes on the synapses e. axon hillocks.
b. membranes on the dendrites
Most of the synapses in vertebrates conduct information in only one direction
because only the postsynaptic cells can bind and respond to neurotransmitters
peritubular capillaries
branches of the efferent arteriole; surround the proximal and distal tubules
Calcitonin is released
by the thyroid gland
glucosuria
can result from diabetes mellitus
efferent arteriole
capillaries converge as they leave the glomerulus and form this
The closest algal relatives of land plants are _____.
charophytes
Antidiuretic hormone (ADH) makes the____permeable to water
collecting duct
Urea diffuses out of the
collecting duct as it traverses the inner medulla
The binding of antibodies to antigens can result in antigen inactivation by which of the following: 1- activation of the complement pathway 2- viral neutralization 3- activation of cytotoxic T cells 4- precipitation of soluble antigens Select one: a. 1 only b. 2,3 c. 2, 3, 4 d. 1, 2, 4
d. 1, 2, 4
When you look at a pine or maple tree, the plant you see is a _____.
diploid sporophyte
when does transit diabetes insipidus occur?
during pregnancy- increase in placental vasopressinase destroys ADH so women lose more water
fever
elevated body temperature in response to a bacterial or viral infection
adrenal medulla
epinephrine and norepinephrine
filtration membrane consists of?
fenestrated capillary endothelium, basement membrane, podocytes
Choose the correct developmental sequence of animal development.
fertilization → cleavage → gastrulation → organogenesis
Excretory structures known as protonephridia are present in
flatworms.
interstitial fluid
fluid that surrounds body cells
where are "filtration slits" found?
formed by the spaces between podocytes that surround glomerular capillaries
respiratory system functions
gas exchange (uptake of oxygen, disposal of carbon dioxide)
Shortly after ingesting a big plate of carbohydrate-rich pasta, you measure your blood's hormone levels. What results would you expect, compared to before the meal?
high insulin, low glucagon
Daughters of women treated with DES are at
higher risk for reproductive abnormalities, including miscarriage, structural changes, and cervical and vaginal cancers
Oxytocin, the milk-release hormone secreted from nerve endings (axon terminals) in the posterior pituitary gland, is synthesized in
hypothalamus
Portal blood vessels connect two capillary beds found in the
hypothalamus and anterior pituitary.
The hypothalamus receives
information from the nervous system and initiates responses through the endocrine system
The three primary waste products found in a representative urine sample are...
ions, metabolites, nitrogenous wastes
To prevent insect pests from maturing into reproducing adults, pest controllers use synthetic agonists of
juvenile hormone.
Organisms categorized as osmoconformers are most likely _____?
marine
For which is the number the same in males and females?
meiotic divisions required to produce each gamete
Jet lag occurs when a person moves rapidly from one time zone to another, causing conflict between the body's biological rhythm and the new cycle of light and dark. Some scientists suspect that jet lag may result from disruption of the daily cycle of secretion of the hormone known as _____.
melatonin
Pheromones
members of the same animal species sometimes communicate with this, chemicals that are released into the environment
A distinction between the functions of the adrenal medulla and the adrenal cortex is that the adrenal cortex responds to a tropic hormone to secrete____ and ____
mineralocorticoids and glucocorticoids .
juxtaglomerular cells
modified smooth muscle cells int he wall of the afferent arteriole
digestive system components
mouth, pharynx, espohagus, stomach, intestines, liver, pancreas anus
too high levels of K in ECF leads to...
neuromuscular function damage
Renin triggers the formation
of the peptide angiotensin 2
Terrestrial animals are _____.
osmoregulators that do not exchange quantities of water by osmosis with the environment
Terrestrial animals are _____.
osmoregulators that must obtain water from the environment
The hypothalamus modulates hormone secretion by the anterior pituitary by means of
peptide hormones
Gigantism, is caused by a tumor that induces the gland in which it develops to overproduce a certain hormone. Where would such a tumor be expected to grow?
pituitary gland
Asexual reproduction ____
produces offspring genetically identical to the parent
The diploid generation of the plant life cycle always _____.
produces spores
Which of the following is a function of meiosis but not mitosis in eukaryotes?
production of animal gametes
An aquatic animal with an internal solute concentration of 500 mOsm/L is placed in a fluid with solute concentration of about 700 mOsm/L. To osmoregulate and survive, the animal must
pump out salts to keep tissue at 500 mOsm/L.
glucocortioids
raise blood glucose level
epinephrine and norepinephrine
raise blood glucose level, increase metabolic activities, constrict certain blood vessels
The activation of the parasympathetic branch of the autonomic nervous system is associated with
resting and digesting.
paracrine
signals act on cells near the secreting cell
Paracrine
signals act on nearby, neighboring cells.
The operation of the sodium-potassium "pump" moves
sodium ions out of the cell and potassium ions into the cell.
Osmoregulation regulates
solute concentrations and balances the gain and loss of water
estrogen
stimulate uterine libing growth, promote development and maintenance of female secondary sex characteristics
angiotensin II
stimulates activity of Na+/H+ antiporters in proximal tubule cells
thyroid hormone
stimulates and maintains metabolic processes
parathyroid hormone
stimulates cells in the distal convoluted tubule to reabsorb more calcium into the blood
The "undershoot" phase of after-hyperpolarization is due to
sustained opening of voltage-gated potassium channels.
The divisions of the nervous system that have antagonistic, or opposing, actions are the
sympathetic and parasympathetic systems.
The point of connection between two communicating neurons is called the
synapse
How is the production of hormones such as thyroxine and estrogen regulated?
the hypothalamus directs the anterior pituitary to produce hormones that then stimulate or inhibit the production of these hormones
Oxytocin secretion and milk release from the mammary glands of lactating female mammals are initiated by _____.
the physical sensation of the baby sucking at the nipple
Oxytocin secretion and milk release from the mammary glands of lactating female mammals are initiated by _____.
the physical sensation of the baby sucking at the nipple; The milk-release response system was given as an example of a neuroendocrine pathway with positive feedback leading to milk release from the nursing mother to the sucking baby. The "neuro" part includes the baby's activation of the mother's mechanoreceptor neurons in the breast.
Gonad
the sex organ where gametogenesis takes place
organs
tissues organized into these functional units
Which of these is an osmoconformer? Bird Tunicate Freshwater flatworms Earthworm Ray-finned fish
tunicate
Mitosis results in the formation of how many cells; meiosis results in the formation of how many cells?
two diploid cells ... four haploid cells
The most abundant solute in urine is _____.
urea (and other nitrogenous wastes)
The primary nitrogenous waste excreted by mammals is
urea, which is less toxic than ammonia
How does renin exit the kidney
via the efferent arteriole
endothermic
warmed mostly by heat generated by metabolism; humans, mammals, birds
filtrate
water and small solutes (salt, sugars, amino acids, nitrogenous wastes) cross the epithelial membrane and form this solution
Luteinizing hormone (LH)
Which hormone stimulates hormone production by the ovaries and testes?
Prolactin
Which hormone stimulates milk production?
What is able to diffuse from the tubule into the interstitial fluid
salt but not water; filtrate becomes increasingly dilute
protonephridia
flatworms have these excretory systems; form a network of dead end tubules; the tubules branch throughout the body, which lacks a coelom or open cavity; serve in osmoregulation
The response of the heating system reduces the stimulus. This is an example of_____feedback.
negative
A paracrine signal that relaxes smooth muscle cells is
nitric oxide.
Adaptations of desert animals do not likely include
nitrogenous waste excreted as ammonia
An appropriate group of animals to examine to observe a Malpighian tubule would be
the insects
The countercurrent multiplier system involving
the loop of Henle maintains a high salt concentration in the kidney
Among the following, the earliest consequence of the acrosomal reaction is ____
the membrane of the egg depolarizing
How are changes in Na concentration detected
osmotic stretch receptors in macula densa response to decrease in tubular Na by releasing chemical messengers that stimulate granular cells to produce renin
Considerable energy is expended to maintain
the osmotic gradient between the medulla and cortex
The increased contraction of the human uterus during labor and delivery is at least partially due to the actions of
oxytocin.
Urine formed by a kidney collects in the ___before being drained from the kidney by the___and transported to the____
renal pelvis....ureter....urinary bladder
reproductive system functions
reproduction
cAMP binds to and activates protein kinase A, which then phosphorylates other enzymes in the signal transduction pathway.
What is the role of cAMP in the signal transduction pathway activated by epinephrine?
gametogenesis
the process of forming sperms and eggs.
They turn genes on or off and it takes time for gene products to build up or become depleted.
What is the primary reason steroid hormones usually act slowly?
The increasing solute concentration of the interstitial fluid results in water leaving the filtrate by osmosis.
...
Freshwater fish excrete nitrogenous wastes as
ammonia
progestins
promote uterine lining growth
proximal convoluted tubule.
The renal corpuscle connects to the loop of Henle. collecting duct. distal convoluted tubule. proximal convoluted tubule
During short-term starvation, most available fuel molecules are catabolized to provide energy for metabolism rather than being used as building blocks for growth and repair, a trade-off that is hormonally regulated by
glucagon.
Adrenocorticotropic hormone (ACTH) triggers the release of _____ in response to stress.
glucocorticoids
adrenal cortex
glucocortioids, mineralocorticoids
what cells produce renin?
granular cells of the afferent arteriole
where is the only place that you can produce aldosterone? what enzyme is involved
glomerular layer of adrenal gland only place with aldosterone synthase
Analysis of a blood sample from a fasting individual who had not eaten for 24 hours would be expected to reveal high levels of
glucagon.
When several EPSPs arrive at the axon hillock from different dendritic locations, depolarizing the postsynaptic cell to threshold for an action potential, this is an example of
spatial summation.
Dendritic cells
specialized white blood cells that patrol the body searching for antigens that produce infections we look at these as scouts that tell about infection
smooth muscle
spindle shaped cells, walls of many organs, involuntary
anitdiuretic hormone (ADH)
stimulates insertion of water-channel proteins (aquaporin-2) into the apical membranes of principal cells
parathryoid hormone (PTH)
stimulates opening of Ca2+ channels in apical membranes of early distal tubule cells
cardiac muscle
striated, forms contractile wall of heart
androgens
support sperm formation, promote development and maintenance of male secondary sex characteristics
aldosterone is secreted by [...] and acts on [...]
suprarenal glands and acts on cortical collecting tubule of kidney
Endocrine
The simplest hormone signaling pathway (the endocrine pathway) is (1) A stimulus causes an endocrine cell to release a hormone. (2) The hormone acts on an effector cell. (3) The effector cell generates a response. This system is used in animals, but not often.
stimulates aldosterone secretion.
Angiotensin II is a potent vasodilator. stimulates aldosterone secretion. is formed from angiotensin I by the action of renin. acts on the collecting ducts to increase reabsorption of water.
The regulation of blood sugar levels and our stress responses are controlled in part by a negative feedback loop involving cortisol, ACTH, and CRH. What would likely be the result during times of stress if cortisol receptors in the hypothalamus were nonfunctional?
Blood sugar levels would rise to dangerous levels.
Which of the following represents the correct sequence of flow through the nephron?
Renal corpuscle > proximal tubule > loop of Henle > distal tubule > collecting duct
Macrophages are ___
large, phagocytic cells that can leave the circulation and enter the tissues of the body
What is the role of ANP on aldosterone regulation?
1. inhibits secretion of aldosterone by adrenal cortex 2. inhibits production of renin by juxtaglomerular apparatus 3. decrease Na reabsorption in collecting duct decreases plasma volume and blood pressure
a Level: 1
2. Which of the following fluid compartments contains the smallest volume of water? A) plasma B) interstitial compartment C) intracellular compartment D) extracellular compartment E) cytoplasm
c Level: 2
20. The primary regulator of plasma sodium concentration is A) renin. B) aldosterone. C) antidiuretic hormone (ADH). D) atrial natriuretic hormone. E) insulin.
d Level: 2
37. The most common cause of hyperkalemia is A) vomiting. B) increased dietary intake. C) increased urinary output. D) cellular injury or death. E) diarrhea.
blood osmolality increases
ADH secretion will increase when blood osmolality increases. blood pressure increases. blood volume increases. blood pH increases.
According to most conservation biologist, the single greatest threat to global biodiversity is _____.
Alteration or destruction of the physical habitat.
The only vertebrates in which blood flows directly from respiratory organs to body tissues without first returning to the heart are the ____.
Fishes.
Which of the following correctly matches a phase of the cell cycle with its description?
G1: follows cell division
FSH and LH
Gonadotropin-releasing hormone (Gn-RH) regulates the release of prolactin and oxytocin. FSH and LH. estrogen and testosterone. progesterone and prolactin.
Against parasites
Mast cells, Eosinophils and basophils
The thermostat is a ____ that detects the stimulus and triggers a response.
Sensor.
Animals that excrete nitrogenous wastes as
ammonia need access to lots of water
What affect does the renal sympathetic nerve have on juxtaglomerular apparatus
baroreceptors detect decrease in pressure and activate renal sympathetic nerve to act on juxtaglomerular apparatus to produce renin
principal cells
cells in the last portion of the distal convoluted tubule and in the collecting ducts; regulated by ADH and aldosterone
In response to stress, the adrenal gland promotes the synthesis of glucose from noncarbohydrate substrates via the action of the steroid hormone
cortisol.
Human sperm cells first arise in the Select one: a. epididymis b. vas deferens c. Sertoli cells d. seminiferous tubules e. prostate gland
d. seminiferous tubules
parathyroid hormone (PTH)
decreased level of plasma Ca2+ promotes release of this hormone from parathyroid glands
how does water move from collecting duct cell into vasa recta (blood)?
down its concentration gradient through constitutively active aquaporin3/4 channels (blood has high osmolality)
what characterizes diabetes insipidus (vs mellitus)
increased volume of hypotonic, tasteless urine vs. hypertonic and sweet urine in mellitus
As plasma osmolality increases, plasma ADH levels...
increase
epithelium
lines intestines; secretes digestive juices and absorbs nutrients
when osmolality is low, osmoreceptor signals are [low/high?]
low
Processing of filtrate in the proximal and distal tubules reabsorbs urea to maintain osmotic balance. achieves the sorting of plasma proteins according to size. regulates the speed of blood flow through the nephrons. maintains homeostasis of pH in body fluids. achieves the conversion of toxic ammonia to less toxic urea.
maintains homeostasis of pH in body fluids.
testes
male gonads
Osmolarity determines the
movement of water across a selectively permeable membrane
Which life cycle stage is found in plants but not animals?
multicellular haploid
What is the basic functional unit of the kidney?
nephron
what is the functional unit of the kidney?
nephron
The osmolarity of the urine is regulated by
nervous and hormonal control
Which category of signal exerts its effects on target cells by binding to membrane-bound receptor proteins?
neurohormones
The Bohr shift on the oxygen-hemoglobin dissociation curve is produced by changes in ____.
pH.
Thyroid hormone refers
to a pair of hormones; Triiodothyronin (T3) with three iodine atoms Thyroxine (T4) with four iodine atoms
Kidney function in amphibians is similar
to freshwater fishes
Diabetes Insipidus [definition]
tremendous secretion of urine (lack of water retention)
renal plasma clearance
volume of blood that is cleared of a substance per unit of time
ADH and RAAS both increase
water reabsorption, but only RAAS will respond to a decrease in blood volume
Two Requirements for a Helper T Cell to Activate Adaptive Immune Responses
- A foreign molecule must be present that can bind specifically to the antigen receptor of the helper T cell - This antigen must be displayed on the surface of an antigen-presenting cell (can be a dendritic cell, macrophage, or naive B cell) which have both class I and class II MHC molecules (class II molecules provide a molecular signature by which an antigen-presenting cell is recognized)
Immune Response of Someone with Type A
- Certain bacteria normally present in the body have epitopes very similar to A and B carbohydrates - By responding to the bacterial epitope similar to the B carbohydrate, a person with type A blood makes antibodies that will react with the type B carbohydrate - No antibodies are made against the bacterial epitope similar to the type A carbohydrate because lymphocytes reactive with the body's own molecules are inactivated or eliminated during development - If the person with type A blood receives a transfusion of type B blood, that person's anti-B antibodies cause an immediate and devastating transfusion reaction - The transfused red blood cells undergo lysis, which can lead to chills, fever, shock, and kidney malfunction (anti-A antibodies in the donated type B blood will act against the recipient's type A red blood cells
Stomata
- Microscopic pores on a leaf that allows CO2 to enter the leaf and oxygen exit
10) Where and from what compound(s) is urea produced? A) liver from NH3 and CO2 B) liver from glycogen C) kidneys from glucose D) kidneys from glycerol and fatty acids E) bladder from uric acid and H2O
A) liver from NH3 and CO2
D. human growth hormone
Abnormally high levels of which anterior pituitary hormone will lead to hyperglycemia? A. thyroid stimulating hormone B. prolactin C. oxytocin D. human growth hormone
D. diabetes insipidis
Abnormally low secretion of ADH from the posterior pituitary gland results in the disease A. myxedema B. cretinism C. diabetes mellitus D. diabetes insipidis
What is true about endocrine glands and the hormones they produce?
Aldosterone produced by the adrenal glands controls the reabsorption of sodium ions by the kidneys; The adrenal glands sit atop the kidneys and secrete a variety of hormones, including aldosterone, which controls the reabsorption of sodium ions by the kidneys.
elevated potassium levels.
Aldosterone secretion may be stimulated by ADH. elevated potassium levels. excess water intake. elevated sodium levels
) ______ is synthesized by neurons in the hypothalamus and released in the posterior pituitary, from where it enters the blood stream and travels to target tissues.
Anti-diurectic hormone (ADH).
Neurons in the hypothalamus produce
Anti-diurectic hormone (ADH).
What hormone promotes water retention by the kidneys?
Antidiuretic hormone (ADH)
) Daphnia, a freshwater crustacean, can reproduce either sexually or asexually. When food is plentiful ______ reproduction is more likely. When the water is clean ______ reproduction is more likely.
Asexual; asexual
58) Gluconeogenesis occurs in the liver due to the action of ________. A) insulin B) cortisol C) aldosterone D) secretin
B
Because antigen receptor genes are randomly rearranged, some immature lymphocytes produce receptors specific for epitopes on the organism's own molecules. Why doesn't the immune system attack these molecules on the body's cells and tissues?
B and T cells with receptors specific for the body's own molecules are destroyed by apoptosis.
6) In addition to their role in gas exchange, fish gills are also directly involved in A) digestion. B) osmoregulation. C) thermoregulation. D) the excretion of uric acid. E) the release of atrial natriuretic proteins.
B) osmoregulation.
Which of the following is the best explanation for why cholesterol decreases the permeability of biological membranes? 1) Because cholesterol is amphipathic, it forms tiny vesicles that trap solutes. 2) Cholesterol has four rings in its structure that can trap solutes. 3) Because cholestrol is amphipathic, it fits in betweem the phospholipids and blocks diffusion through the membrane. 4) Cholesterol binds to the outside surface of a membrane, thus blocking the movement of solutes.
Because cholesterol is amphipathic, it fits in between the phospholipids and blocks diffusion through the membrane.
42) The endocrine system and the nervous system are chemically related. Which of the following substances best illustrates this relationship? A) estrogen B) calcitonin C) norepinephrine D) calcium E) ecdysone
C
49) A disease that destroys the adrenal cortex should lead to an increase in the plasma levels of A) glucocorticoid hormones. B) epinephrine. C) adrenocorticotropic hormone (ACTH). D) glucose. E) acetylcholine.
C
77) A portal vessel carries blood from the hypothalamus directly to the A) thyroid. B) pineal gland. C) anterior pituitary. D) posterior pituitary. E) liver.
C
79) The main target organs for tropic hormones are A) muscles. B) blood vessels. C) endocrine glands. D) kidneys. E) nerves.
C
99) A man has been told that he is not synthesizing enough follicle-stimulating hormone (FSH), and for this reason he may be unable to father a child. Choose the correct statement to explain this problem. A) The physician is wronga hormone made in the adenohypophysis could not influence fertility. B) The man must be producing progesterone, which inhibits the synthesis of FSH. C) FSH stimulates sperm production in the testes. D) FSH stimulates estrogen secretion by ovarian cells; therefore it is not synthesized by males.
C
61) Which of the following animals generally has the lowest volume of urine production? A) a marine shark B) a salmon in freshwater C) a marine bony fish D) a freshwater bony fish E) a shark inhabiting Lake Nicaragua
C) a marine bony fish
22) What is the functional unit of the kidney? A) cortex B) vasa recta C) nephron D) bladder E) glomerulus
C) nephron
50) The ________ are the major blood vessels transporting blood to the kidneys. A) pulmonary arteries B) glomerulus C) renal arteries D) renal veins E) venae cavae
C) renal arteries
52) The movement of substances from the blood into the proximal tubule is known as A) filtration. B) dialysis. C) secretion. D) reabsorption E) none of these
C) secretion.
101) Thyroxine is a peptide hormone, but its mechanism is different from other peptide hormones. Which of the following statements is true concerning this difference? A) It causes positive feedback. B) It is a stimulant of cellular metabolism and targets all cells. C) It is very specific in the cell type it targets. D) It does not require a second messenger to effect a response.
D
19) Where is it likely that you will find the receptor molecules for chemical signals? A) in the nucleus of target cells B) in the interstitial fluid surrounding target cells C) in the cytoplasm of target cells D) in the cell membrane of target cells E) associated with the DNA of target cells
D
26) Which of the following statements about the hypothalamus is incorrect? A) It functions as an endocrine gland. B) It is part of the central nervous system. C) It is subject to feedback inhibition by certain hormones. D) It secretes tropic hormones that act directly on the gonads. E) Its neurosecretory cells terminate in the posterior pituitary.
D
29) Which of the following have nontropic effects only? A) FSH B) LH C) TSH D) MSH E) ACTH
D
4) What do nitric oxide and epinephrine have in common? A) They both function as neurotransmitters. B) They both function as hormones. C) They are both involved in the "fight-or-flight" response. D) Only A and B are correct. E) A, B, and C are correct.
D
17) For hormones that homeostatically regulate cellular functions, A) negative feedback typically regulates hormone secretion. B) the circulating level of a hormone is held constant through a series of positive feedback loops. C) both lipid-soluble hormones and water-soluble hormones bind to intracellular protein receptors. D) endocrine organs release their contents into the bloodstream via specialized ducts. E) it is impossible to also have neural regulation of that system.
E
42) A toxin that specifically blocks active transport in the loop of Henle might result in which of the following? A) a decrease in the interstitial concentration of NaCl B) a decrease in the filtrate concentration ability of the kidney C) an increase in the amount of interstitial urea to maintain interstitial osmolarity D) A and C only E) A, B and C
E) A, B and C
5) Which feature of osmoregulation is found in both marine and freshwater bony fish? A) loss of water through the gills B) gain of salt through the gills C) loss of water in the urine D) no drinking of water E) gain of water through food
E) gain of water through food
Endocrine
Endocrine signals act on distant cells and are carried by blood or body fluids. Endocrine signals are, by definition, hormones. Cells that produce endocrine signals may be organized into discrete organs called glands, or they may be interspersed
) Which of the following hormones is water-soluble and therefore must bind to a receptor on the surface of a target cell?
Epinephrine
Which of these is a nonsteroid hormone? estrogen testosterone both estrogen and testosterone oxytocin epinephrine and oxytocin
Epinephrine and oxytocin
) Luteinizing hormone is released into the ovaries during pregnancy. (T,F) Follicle stimulating hormone is released into the ovaries during pregnancy. (T,F)
F; F
Animals that migrate great distances would obtain the greatest energetic benefit of storing chemical energy as ____.
Fats.
A. iodine
For the formation of thyroxine to occur, it is essential that _____ be present. A. iodine B. calcitonin C. calcium D. iron
An amino acid that operates at inhibitory synapses in the brain is
GABA
Incorrect
GFR increases when blood flow into glomerular capillaries decreases
What is the biological significance of genetic diversity between populations?
Genes for traits conferring an advantage to local conditions make microevolution possible.
0 mmHg
Given the following values, calculate the net filtration pressure: 1. glomerular blood hydrostatic pressure = 40 mmHg, 2. capsular hydrostatic pressure = 10 mmHg, 3. blood colloid osmotic pressure = 30 mmHg.
Shortly after ingesting a big plate of carbohydrate-rich pasta, you measure your blood's hormone levels. What results would you expect, compared to before the meal?
High insulin, low glucagon
Nonsteroid hormones act via signal transduction pathways; steroid hormones do not act via signal transduction pathways.
How do nonsteroid hormones differ from steroid hormones?
) In the human reproductive cycle, _______, prevents the corpus luteum from degenerating after an embryo has become implanted in the uterine lining.
Human chorionic gonadotropin (hCG), synthesized by embryonic cells
C. prostaglandins
In 1971, it was discovered that aspirin exerts its effect in reducing pain and inflammation by blocking the chemical synthesis of A. glucocorticoids B. norepinephrine C. prostaglandins D. melatonin
Hypoglycemia, or low levels of glucose in the blood of a healthy human, is "corrected" by an _____.
Increase in the secretion of glucagon.
Which hormone stimulates hormone production by the ovaries and testes?
Luteinizing hormone (LH)
Processing of filtrate in the proximal and distal tubules accomplishes what important function?
Maintaining a constant pH in body fluids
Which of the following molecules that control the hunger response is(are) NOT (a) polypeptide hormone(s)?
Malonyl-CoA
Which of the following statements about the pituitary gland is false?
Neurosecretory cells produce hormones that are stored in the anterior pituitary.
Select the correct statement about osmolarity. Osmolarity measures the moles of solute per liter of solution. The contents of an animal cell are hyperosmotic. If two solutions are separated by a selectively permeable membrane, water flows by osmosis from a hyperosmotic solution to a hypoosmotic one.
Osmolarity measures the moles of solute per liter of solution.
) The enzyme that makes vitamin D in the kidneys is induced by parathyroid hormone from the
Parathyroid glands
) The adrenal glands produce all of the following EXCEPT
Parathyroid hormone (PTH).
You have a planar bilayer with equal amount of saturated and unsaturated phospholipids. After testing the permeability of this membrane to glucose, you increase the proportion of unsaturated phospholipids n the bilayer. What will happen to the membrane's permeability to glucose?
Permeability to glucose will increase.
Gigantism, a condition characterized by exceptionally rapid growth, is sometimes caused by a tumor that induces the gland in which it develops to overproduce a certain hormone. Where would such a tumor be expected to grow?
Pituitary gland
Gigantism, a condition characterized by exceptionally rapid growth, is sometimes caused by a tumor that induces the gland in which it develops to overproduce a certain hormone. Where would such a tumor be expected to grow?
Pituitary gland.
) In the human menstrual cycle, the corpus luteum secretes large amounts of
Progesterone.
...
Questions 81 through 83 are all based on the following case study: You have just admitted Mary Roberts, a 70-year-old woman, to the hospital for GI bleeding. Her blood pressure is 130/80, pulse 80/min and irregular, respirations 18/min, and temperature 99.2. Mrs. Roberts denies pain at this time although she appears anxious and very pale. Her medical history includes lung cancer that was diagnosed two weeks ago, peptic ulcer disease with reflux esophagitis, and "fluid retention". Admission lab work shows a plasma Na+ of 152 mEq/L and K+ of 2.8 mEq/L.
Which molecules determine the tissue specificity of hormones?
Receptors
The alpha-helix is a component of _____ protein structure.
Secondary
Nucleus
Steroid hormone-receptor complexes act in the _____.
Which type of hormone is lipid soluble?
Steroids
LH
Synthesis of progesterone in the ovary and testosterone in the testis is stimulated by LH. MSH. TSH. ACTH
B. anterior pituitary
Target cells for hypothalamic releasing hormones are in the A. hypothalamus B. anterior pituitary C. posterior pituitary D. thyroid
B. beta
The _____ cells of the islets of Langerhans secrete insulin. A. alpha B. beta C. delta D. gamma
Why would life tables constructed in ancient Rome be different than those constructed for today's Romans?
The fecundity of today's individuals is lower. Because survivorship is increased, families tend to have fewer offspring. Also, modern birth control methods have reduced overall fecundity.
both a and b
The filtrate that drips from the renal papillae into the calyces as urine has a higher concentration of waste products (urea) than the original filtrate. may have lost up to 99% of its original volume. both a and b neither a nor b
What is the "twofold" cost of sex?
The higher number of female offspring produced by an asexual female
C. sodium
The most abundant cation in plasma is _______. A. phosphate B. potassium C. sodium D. chloride
C. oxytocin and antidiuretic hormone
The posterior pituitary gland stores and secretes A. prolactin and follicle stimulating hormone B. human growth hormone and thyroid stimulating hormone C. oxytocin and antidiuretic hormone D. glucocorticoids and androgens
) In traveling from the epididymis, human sperm first acquire fluid from
The seminal vesicle.
nephrons.
The structural and functional units of the kidney are called nephrons. renal papillae. renal pyramids. renal columns.
The velocity of blood flow is the lowest in capillaries because _____.
The total cross-sectional area of the capillaries is greater than the total cross-sectional area of the arteries or any other part of the circulatory system.
renal pelvis.
The ureter expands into the substance of the kidney as the hilum. renal pelvis. renal capsule. renal pyramid
collects excess water and solutes from the medullary interstitial fluid.
The vasa recta supplies blood to the glomerulus. alters the cortical solute gradient. collects excess water and solutes from the medullary interstitial fluid. collects water and solutes reabsorbed from the proximal tubule.
When a cell is in equilibrium with its environment, which of the following occurs for substances that can diffuse through the cell? 1) There is directed movement of substances into and out of the cell. 2) There is random movement of substances into and out of the cell. 3) There is no movement of substances into and out of the cell. 4) All movement of molecules is directed by active transport.
There is random movement of substances into and out of the cell.
Which statement best describes tissue macrophages?
They are large, phagocytic cells that can leave the circulation and enter the tissues of the body.
Which of the following is true of kinetochores?
They are sites at which microtubules attach to chromosomes.
How are the human penis and clitoris similar?
They develop from the same population of embryonic cells.
Why is it difficult to observe individual chromosomes with a light microscope during interphase?
They have uncoiled to form long, thin strands.
Which of the following is not true about helper T cells?
They recognize polysaccharide fragments presented by class II MHC molecules.
What is the function of endocrine glands?
They release hormones into the bloodstream for distribution around the body
What is the function of endocrine glands?
They release hormones into the bloodstream for distribution around the body.
D. iodine and tyrosine
Thyroid hormones are synthesized in thyroglobulin from A. iron and tyrosine B. iodine and tryptophan C. phosphorus and arginine D. iodine and tyrosine
) The anterior pituitary synthesizes all of the following hormones EXCEPT
Thyrotropin-releasing hormone (TRH)
) Which of the following hormones is lipid-soluble?
Thyroxin
Unlike most bony fishes, sharks maintain body fluids that are isoosmotic to seawater, so they are considered by many to be osmoconformers. Nonetheless, these sharks osmoregulate at least partially by _____?
Tolerating high urea concentrations that balance internal salt concentrations to seawater osmolarity
Hibernation and estivation during seasons of environmental stress are both examples of ____.
Torpor.
B. anterior pituitary
Tropic hormones are secreted by the A. adrenal cortex B. anterior pituitary C. hypothalamus D. parathyroid glands
Which of the following ecological locations has the greatest species diversity? 1) Deciduous forests 2) Islands 3) Tropical rain forest 4) Tundra 5) Grasslands
Tropical rain forests
57) All adenohypophyseal hormones except GH affect their target cells via a cyclic AMP second messenger.
True
True or false? The pancreas is responsible for producing hormones that maintain the homeostatic levels of glucose in the blood.
True; The pancreas produces two hormones, insulin and glucagon, which work together to maintain the homeostatic levels of glucose in the blood.
C. over 35 years in age
Type II diabetes most often occurs in humans who are overweight and A. in their early childhood B. between 10 and 20 years of age C. over 35 years in age D. elderly, usually over 65
Which of the following statements about blood circulation in the body is true? 1) During one cardiac cycle, the two ventricles contract first, and then the two atria contract. 2) As the right ventricle contracts, it sends oxygenated blood through the aorta to all tissues of the body. 3) Deoxygenated blood flowing through the pulmonary veins is carried to the right atrium. 4) Valves prevent the back-flow of blood into the atria and ventricles.
Valves precent the back-flow of blood into the atria and ventricles.
Which of the following events would be predicted by the Bohr shift effect as the amount of carbon dioxide released from your tissues into the blood capillaries increases? The amount of oxygen in _____. 1) venous blood would increase 2) arterial blood would increase 3) venous blood would decrease 4) arterial blood would decrease
Venous blood would decrease
Receptors. Hormones bind to receptors on target cells and trigger a cellular response.
Which molecules determine the tissue specificity of hormones?
A. pancreas
Which of the following has both endocrine and exocrine functions? A. pancreas B. anterior pituitary C. thyroid D. adrenal medulla
Na+/H+ antiporters
a secondary active transport process that achieves Na+ reabsorption, returns filtered HCO3- and water to the peritubular capillaries, and secretes H+
A strong antibody response ('humoral immunity') to a pathogen requires which of the following ? Select one: a. B cells and helper T cells b. Cytotoxic T cells and helper T cells c. Cytotoxic T cells d. B cells only e. Helper T cells only
a. B cells and helper T cells correct
Why are action potentials usually conducted in one direction? Select one: a. The brief refractory period prevents reopening of voltage-gated Na+ channels. b. The axon hillock has a higher membrane potential than the terminals of the axon. c. Ions can flow along the axon in only one direction d. Voltage-gated channels for both Na+ and K+ open in only one direction e. The nodes of Ranvier conduct potentials in one direction.
a. The brief refractory period prevents reopening of voltage-gated Na+ channels.
A cell type that interacts with both the humoral and cell-mediated immune pathways is a Select one: a. helper T cell. b. natural killer cell c. CD8 cell d. cytotoxic T cell e. plasma cell
a. helper T cell. correct
The suprachiasmatic nuclei are found in the Select one: a. hypothalamus b. thalamus c. amygdala d. Broca's area. e. epithalamus
a. hypothalamus
A toxin that binds specifically to voltage-gated sodium channels in axons would be expected to Select one: a. prevent the depolarization phase of the action potential. b. increase the release of neurotransmitter molecules. c. prevent graded potentials d. prevent the hyperpolarization phase of the action potential e. have most of its effects on the dendritic region of a neuron
a. prevent the depolarization phase of the action potential.
The operation of the sodium-potassium "pump" moves Select one: a. sodium ions out of the cell and potassium ions into the cell. b. sodium and potassium ions into the cell. c. sodium and potassium ions out of the cell d. sodium and potassium ions into the mitochondria e. sodium ions into the cell and potassium ions out of the cell.
a. sodium ions out of the cell and potassium ions into the cell.
A function-disrupting mutation in the progesterone receptor gene would likely result in Select one: a. the inability of the uterus to support pregnancy b. the absence of secondary sex characteristics. c. the absence of mammary gland development d. enlarged and hyperactive uterine endometrium e. the absence of pituitary gonadotropin hormones.
a. the inability of the uterus to support pregnancy
The autonomic nervous system includes an endocrine gland known as the
adrenal medulla
A fantasy movie features a caterpillar that never matures into an adult, but simply gets larger and larger with each molt. It might be possible that the caterpillar did not mature into an adult because of
an increased level of juvenile hormone.
One reason a person might be severely overweight is due to
an undersecretion of thyroxine.
Urine is produced by many species in four steps. These steps are : 1. Excretion 2. Reabsorption 3. Secretion 4. Filtration. The correct order of these steps is: Select one: a. 2, 3, 4, 1 b. 4, 2, 3, 1 c. 4, 2, 1, 3 d. 2, 3, 1, 4, e. 3, 4, 2, 1
b. 4, 2, 3, 1
Select the correct statement about feedback regulation in endocrine systems. Select one: a. A hormone cascade pathway involves the hypothalamus, posterior pituitary, and endocrine gland. b. Some homeostatic control systems rely on pairs of negatively regulated hormone pathways, each counterbalancing the other. c. All hormones are regulated by negative feedback loops. d. All hormones are regulated by positive feedback loops.
b. Some homeostatic control systems rely on pairs of negatively regulated hormone pathways, each counterbalancing the other.
Innate immunity and acquired immunity are both __
characteristics of all vertebrate animals
CVD
coronary vascular disease Leading cause of death in the US
The outer part of the kidney is the
cortex
The outer part of the kidney is the _____.
cortex
One of your neurons has been infected by Varicella zoster virus, which causes chickenpox. Which of the following will 'present' fragments of the virus on the surface of the neuron after infection? Select one: a. CD4 receptor b. MHC Class II molecule c. T cell receptor d. MHC Class I molecule e. CD8 receptor
d. MHC Class I molecule
All of the following are examples of amplification of a hormone signal except ________.
different cell types have different receptors capable of binding the same hormone.
Vinblastine is a standard chemotherapeutic drug used to treat cancer. Because it interferes with the assembly of microtubules, its effectiveness must be related to
disruption of mitotic spindle formation.
What is an example of a non steroid hormone?
epinephrine and oxytocin
kidney
functions in osmoregulation and excretion; consist of tubules; transport and store urine
Adrenocorticotropic hormone (ACTH) triggers the release of _____ in response to stress.
glucocorticoids ( In response to stress, ACTH stimulates the adrenal cortex to secrete glucocorticoids.)
The "reproductive handicap" for sexual reproduction refers to __
have only half the offspring are females
Which of the following traits was most important in enabling the first plants to move onto land?
he development of sporopollenin to prevent the desiccation of zygotes
Which of the following cell types does HIV preferentially infect?
helper T cells
what signs would indicate the condition of glomerulonephritis?
hematuria (blood in urine), proteinuria (excess protein in urine), increased urine output, edema
What is the driving force for the filtration of blood by the renal corpuscle?
higher pressure in glomerular capillaries than in surrounding Bowman's capsule
Excretory organs known as Malpighian tubules are present in
insects.
Which hormone is incorrectly paired with its action?
insulin stimulates glycogen breakdown in the liver
After eating a carbohydrate-rich meal, the mammalian pancreas increases its secretion of
insulin.
A primary reason for needing a new vaccine for influenza each year is that ___
mutation in the influenza virus is frequent
In the sequence of permeability changes for a complete action potential, the first of these events that occurs is the
opening of voltage-gated sodium channels.
The process of coating a pathogen with antibodies, thereby promoting its subsequent phagocytosis
opsonization
How is osmolality detected?
osmoreceptors are sensitive to changes in osmolality (amount of fluid in interstitial space)
Terrestrial animals are
osmoregulators that must obtain water from the environment
PTH
raises blood calcium level
glucagon
raises blood glucose level
The kidneys are paired organs that
regulate water and electrolyte balance in terrestrial vertebrates
Oxytocin
regulates milk secretion by the mammary glands
Mammals in fresh water have
relatively short loops
he sense described as umami is one of _____
savory and delicious sensation on the tongue
Sperm develop in the _____.
seminiferous tubules
Excretory systems regulate
solute movement between internal fluids and the external environment
Organ X produces hormone A, which stimulates target cells Y to produce product Z. Negative-feedback regulation is best represented by observing that
source X has receptor proteins for Z; Without receptors for Z, the source of A (organ X) would not have the idealized feedback mechanism.
In seedless plants, a fertilized egg will develop into _____.
sporophyte
Ecdysone is a(n)
steroid hormone.
The cortical reaction of sea urchin eggs functions directly in
the formation of a fertilization envelope
The primary reason steroid hormones usually act slowly is that
they turn genes on or off and it takes time for gene products to build up or become depleted
How is osmotic pressure created?
when 2 compartments are separated by a semipermeable membrane (permeable to water but selective permeability to solutes)
Wavelength
- Distance between the crests of the electromagnetic waves is called the wavelength - Range from less than a nm for gamma rays to more than a km for radio waves
How Electrons in NADH Finally Reach Oxygen
- Each NADH molecule formed represents stored energy that can be tapped to make ATP when the electrons complete their "fall" down an energy gradient from NADH to oxygen - In cell respiration, the hydrogen that reacts with oxygen is derived from organic molecules rather than H2 and an electron transport chain is used to break the fall of electrons to oxygen in several energy-releasing steps
Immune System
- Enables an animal to avoid or limit many infections - A foreign molecule or cell doesn't have to be pathogenic to elicit an immune response
Oxidative Phosphorylation
- Energy released at each step of the electron transport chain is stored in a form the mitochondrion (or prokaryotic cell) can use to make ATP from ADP - Powered by the redox reactions of the electron transport chain - Accounts for almost 90% of the ATP generated by cell respiration
Electromagnetic Spectrum
- Entire range of radiation
Breakdown of Glucose (general)
- Exergonic - Free energy change of -686 kcal per mole of glucose decomposed - Reaction will occur spontaneously
Tally of Molecules in Citric Acid Cycle
- For each acetyl group entering the cycle, 3 NAD+ are reduced to 3 NADH (steps 3, 4, and 8) - Electrons are transferred to FAD in step 6, which accepts 2 electrons and 2 protons to become FADH2 - In many animal tissue cells, step 5 produces a guanosine triphosphate (GTP) molecule by substrate-level phosphorylation - OVERALL, (for both molecules of acetyl CoA) you get 6 NADH, 2 FADH2, loss of 4 CO2
T Cell-Dependent Activation of B Cells
- Generally, B cell activation by an antigen is aided by cytokines secreted from helper T cells that have encountered the same antigen - Stimulated by both an antigen and cytokines, the B cell proliferates and differentiates into memory B cells and plasma cells - Macrophage or dendritic cell can present fragments from a wide variety of protein antigens, whereas a B cell presents only the antigen to which it specifically binds - When an antigen first binds to receptors on the surface of a B cell, the cell takes in a few foreign molecules by receptor-mediated endocytosis - The class II MHC protein of the B cell then presents an antigen fragment to a helper T cell (this direct cell-to-cell contact is usually critical to B cell activation - An activated B cell gives rise to thousands of identical plasma cells (these cells stop expressing a membrane bound antigen receptor and begin secreting approximately 2,000 antibodies every second of the cells 4 to 5 day life span) - Most antigens recognized by B cells contain multiple epitopes so exposure to a single antigen normal activates a variety of B cells, with different plasma cells producing antibodies directed against different epitopes on the common antigen 1) After an antigen-presenting cell engulfs and degrades a pathogen, it displays an antigen fragment complexed with a class II MHC molecule. A helper T cell that recognizes the complex is activated with the aid of cytokines secreted from the antigen presenting cell 2) When a B cell with receptors for the same epitope internalizes the antigen, it displays an antigen fragment on the cell surface in a complex with a class II MHC molecule. An activated helper T cell bearing receptors specific for the displayed fragment binds to the B cell. This interaction, with the aid of cytokines from the T cell, activates the B cell 3) The activated B cell proliferates and differentiates into memory B cells and antibody-secreting plasma cells. The secreted antibodies are specific for the same antigen that initiated the response
Tallying Cell Respiration
- Glucose is oxidized to 6 molecules of CO2 - Phosphorylation and redox reactions are not directly coupled to each other so the ratio of the NADH molecules to ATP molecules is not a whole number - 1 NADH results in 10 H+ being transported across the inner mitochondrial membrane - 1 NADH generates enough proton motive force for about 2.5 ATP - 1 FADH2 generates enough proton motive force for about 1.5 ATP - If all the proton motive force generated by the electron transport chain were used to drive ATP synthesis there would be 28 ATP produced by oxidative phosphoyrlation plus 4 net from substrate-level phosphorylation for a total of 32 ATP, but only about 30 if the less efficient shuttle were functioning - About 34% of the potential chemical energy in glucose has been transferred to ATP (rest of energy in glucose is lost as heat to help maintain our high body temperature)
Equation for Photosynthesis
- Glucose is used to simplify the relationship between photosynthesis and respiration, but the direct product of photosynthesis is actually a three carbon sugar that can be used to make glucose - 6CO2 + 6H2O + Light Energy --> C6H12O6 + 6O2
Photosynthesis
- Life on earth is solar powered - Chloroplasts of plants capture light energy and convert it to chemical energy that is stored in sugar and other organic molecules - Nourishes nearly the entirely living world directly and indirectly - Occurs in algae, certain other protists, and in some prokaryotes too
Photons
- Light behaves as though it consists of discrete particles - Not tangible objects, but they act like objects in that each of them has a fixed quantity of energy - Amount of energy is inversely related to the wavelength of the light: The shorter the wavelength, the greater the energy of each photon of the light
Chlorophyll
- Light energy absorbed by chlorophyll drives the synthesis of organic molecules in the chloroplast
Tissue and Organ Transplants
- MHC molecules stimulate the immune response that leads to rejection - Each vertebrate species has many alleles for each MHC gene, enabling presentation of antigen fragments that vary in shape and net electrical charge - Diversity of MHC molecules almost guarantees that no two people, except identical twins, will have exactly the same set - To minimize rejection, physicians use donor tissue bearing MHC molecules that match those of the recipient as closely as possible and the recipient takes medicines that suppress immune responses (but that also leaves the recipient more susceptible to infections) - Transplants of bone marrow from one person to another can also cause an immune reaction, but for a different reason - Bone marrow transplants are used to treat leukemia and other cancers as well as various hematological (blood cell) diseases - Prior to receiving transplanted bone marrow the recipient is typically treated with radiation to eliminate his or her own bone marrow cells, thus destroying the source of abnormal cells - This treatment effectively obliterates the recipient's immune system, leaving little chance of graft rejection (however lymphocytes in the donated marrow may react against the recipient; this graft versus host reaction is limited if the MHC molecules of the donor and recipient are well matched)
Splitting of Water
- O2 given off by plants is derived from H2O and not from CO2 - Chloroplast splits water into hydrogen and oxygen
P680 vs. P700
- P680 and P700 are nearly identical chlorophyll a molecules, but their association with different proteins in the thylakoid membrane affects the electron distribution in the two pigments and accounts for the slight differences in their light-absorbing properties
Chemiosmosis
- The process, in which energy stored in the form of a hydrogen ion gradient across a membrane is used to drive cellular work such as the synthesis of ATP - Osmosis refers to the flow of H+ across a membrane - In general, chemiosmosis is an energy-coupling mechanism that uses energy stored in the form of an H+ gradient across a membrane to drive cellular work
Polyclonal Antibodies
- The products of many different clones of plasma cells, each specific for a different epitope - Antibodies that an animal produces after exposure to a microbial antigen are polyclonal - Plasma cells typically have abundant endoplasmic reticulum, a common feature of cells dedicated to making proteins for secretion (TEM)
Helper T Cell (general)
- Triggers both the humoral and cell-mediated immune responses - Helper T cells do not actually carry out those responses though - Signals from helper T cells initiate production of antibodies that neutralize pathogens and activate T cells that kill infected cells
Lymphocytes
- Type of white blood cell in the vertebrate immune system - Originates from stem cells in the bone marrow like all blood cells - Receptor diversity and self tolerance arise as a lymphocyte matures - Proliferation of cells and the formation of immunological memory occur later, after a mature lymphocyte encounters and binds to a specific antigen
Leaf Veins
- Water absorbed by the roots is delivered to the leaves in veins - Veins also export sugar to roots and other nonphotosynthetic parts of the plant
Passive Immunity
- When IgG antibodies in the blood of a female cross the placenta to her fetus--the transferred antibodies can immediately react with any pathogens for which they are specific - Antibodies provided by the mother guard against pathogens that have never infected the newborn - Because passive immunity doesn't involve the recipient's B and T cells, it persists only as long as the transferred antibodies last (a few weeks to a few months) - After giving birth, a nursing mother continues to transfer protection against disease to her infant because of IgA antibodies present in breast milk that provide additional passive immunity to the infant's digest tract while the immune system develops
How a Photosystem Harvests Light
- When a photon strikes a pigment molecule in a light-harvesting complex, the energy is passed from molecule to molecule until it reaches the reaction-center complex - Then an excited electron from the special pair of chlorophyll a molecules is transferred to the primary electron acceptor
Cancer and Immunity
- When adaptive immunity is inactivated the frequency of certain cancers increases dramatically - The risk of developing Kaposi's sarcoma is 20,000 times greater for untreated AIDS patients than for healthy people - If the immune system recognizes only nonself, it should fail to recognize the uncontrolled growth of self cells that is the hallmark of cancer - Viruses are involved in about 15-20% of all human cancers - Six viruses that can cause cancer in humans
Which of these observations illustrate the developmental plasticity of the human nervous system?
-A person suffering from phantom limb pain following amputation may stop feeling pain after viewing a reflection of the remaining limb in a mirrored box. -When activity at a synapse correlates with the activity of other synapses, that synaptic connection is reinforced.
Identify the role(s) of follicle-stimulating hormone (FSH) in human reproduction.
-FSH stimulates the growth of new follicles in the ovary. -FSH promotes the activity of Sertoli cells, which nourish sperm developing within seminiferous tubules.
ADH increases the water permeability of the distal tubule and collecting duct, increasing the amount of water reabsorbed into the surrounding tissue and decreasing the amount lost as urine.
...
ADH is released from the posterior pituitary gland in response to increased blood osmolarity. Dehydration, sweating, and eating salty foods can all cause blood osmolarity to rise. To counteract that change, ADH acts on the distal tubules and collecting ducts, causing them to become more permeable to water. As a result, water is reabsorbed, lowering blood osmolarity, concentrating the urine, and reducing urine volume.
...
Active transport is used to move molecules against a concentration gradient -- from where they are less concentrated to where they are more concentrated. Active transport requires energy from cells.
...
Aldosterone is released from the adrenal glands in response to a drop in blood pressure or blood volume. Blood loss and severe diarrhea can both cause blood pressure and blood volume to drop. To counteract those changes, aldosterone acts on the distal tubules, causing them to reabsorb more Na+ and water. The reabsorption of both sodium and water results in an increase in blood volume and blood pressure without changing blood osmolarity.
...
Antidiuretic hormone (ADH) and aldosterone are two of the hormones that help to regulate blood osmolarity, blood pressure, and blood volume by acting on the kidney.
...
Filtration occurs at the glomerulus-Bowman's capsule interface, sometimes called the renal corpuscle.
...
Filtration, reabsorption, and the establishment of an osmotic gradient by these regions of the nephron are largely unregulated.
...
Finally, the urine is expelled from the body through the urethra.
...
Fluid from the glomerulus first collects in Bowman's capsule.
...
In fresh water, fish can use the abundant water passing through their gills to excrete ammonia rapidly enough so that it never reaches toxic levels in the blood. Ammonia is the easiest, lowest energy nitrogenous waste.
...
Nephrons perform the work required to maintain water and electrolyte balance.
...
The active transport of NaCl in the loop of Henle and collecting duct requires a significant amount of energy. This transport, along with other active transport systems in the kidney, explains why the kidney has one of the highest metabolic rates of any organ in the body.
...
The blood pressure in the glomerular capillaries is higher than in the Bowman's capsule, so water and small solutes are forced out of the blood through capillary pores, leaving the larger components of the blood behind.
...
The filtrate then travels through the rest of the nephron and drains into the collecting duct.
...
The filtrate, now called urine, exits the kidney through a ureter that drains into the urinary bladder.
...
The nephron is the functional unit of the kidney, meaning that filtrate is processed in the nephrons.
...
The osmolarity of the filtrate increases from 300 to 1,200 mOsm/L as it moves down the descending limb of the loop of Henle.
...
The osmotic gradient in the interstitial fluid is maintained mostly by NaCl and urea. In the thin portion of the ascending limb of the loop of Henle, NaCl diffuses out of the nephron. In the thick upper portion of the ascending limb, NaCl is actively transported out of the nephron. (The ascending limb is impermeable to water, which helps maintain high osmolarity in the interstitial fluid.) Urea diffuses out of the lower portion of the collecting duct and is responsible for the high osmolarity in the inner medulla.
...
The production of concentrated urine by the kidneys requires both passive and active transport.
...
The reabsorption of glucose requires the expenditure of energy.
...
The solute concentration of the interstitial fluid increases along a gradient running from the exterior of the kidney to the center of the kidney.
...
The steep osmotic gradient created along the loop of Henle allows water and salts to be returned to the body.
...
The urethra transports urine from the urinary bladder to the world outside the body.
...
The word "renal" refers to a kidney. Recall that arteries transport blood away from the heart. Renal arteries transport blood to the kidneys.
...
This adrenal steroid increases the amount of sodium ion reabsorption by the nephron, which draws more water back from the nephron.
...
Urine formation in mammals starts with filtration by the renal corpuscle. The volume and composition of the filtrate is modified as it progresses through the proximal tubule, loop of Henle, and distal tubule. Final adjustments to the filtrate take place in the collecting duct.
...
Water is reabsorbed in the kidney because of the osmotic gradient established in the interstitial fluid. The osmolarity of the interstitial fluid increases deeper into the medulla. As a result, water diffuses out of the descending limb of the loop of Henle and out of the collecting duct, flowing from areas of lower osmolarity in the filtrate to areas of higher osmolarity in the interstitial fluid. This water diffuses into blood vessels surrounding the nephron, called the vasa recta, returning to the bloodstream and therefore not diluting the osmotic gradient.
...
The secretion of androgens is regulated by a _____ feedback mechanism involving the _____ and _____.
negative ... hypothalamus ... pituitary gland
nervous system
neurons transmit signals along dedicated routes connecting specific locations in the body
The process by which antibodies bind to antigens on the surface of a virus and block its ability to bind to a host cell is called
neutralisation
secretion
non essential solutes and wastes are left in the filtrate or are added to it by this; occurs by active transport
How do nonsteroid hormones differ from steroid hormones?
nonsteroid hormones act via signal transduction pathways; steroid hormones do not act via signal transduction pathways ( Since they do not enter the cell, nonsteroid hormones act via signal transduction pathways.)
Steroid hormone-receptor complexes act in _____.
nucleus
osmolarity
osmotic pressure; total solute concentration expressed a osmolarity, that is, moles of solute per liter of solution
The endocrine glands include the
parathyroid glands.
Birds, insects, and many reptiles excrete nitrogenous waste in the form of uric acid. An advantage of excreting uric acid is that it ____, but a disadvantage is that it _____.
saves water ... costs energy
The fluid with the highest osmolarity is
seawater in a tidal pool
hormones
signaling molecules broadcast throughout the body by the endocrine system
atrial natriuretic peptide (ANP)
suppresses reabsorption of Na+ and water in proximal tubule and collecting duct; also inhibits secretion of aldosterone and ADH
A cell with membrane-bound proteins that selectively bind a specific hormone is called that hormone's
target cell.
Peaks of LH and FSH production occur during
the period just before ovulation
The openings of the urethra and the two ureters mark an area on the internal surface of the urinary bladder called the...
trigone
Embryonic cells especially active in assuring nutritional exchange between a pregnant woman and her embryo are found in
trophoblast
Closer Look at the Citric Acid Cycle
1) Acetyl Co A adds its two-carbon acetyl group to oxaloacetate, producing citrate 2) Citrate is converted to its isomer, isocitrate, by removal of one water molecule and addition of another 3) Isocitrate is oxidized, reducing NAD+ to NADH. Then the resulting compound loses a CO2 molecule forming α-Ketoglutarate 4) Another CO2 is lost, and the resulting compound is oxidized, reducing NAD+ to NADH. The remaining molecule is then attached to coenzyme A by an unstable bond to form Succinyl CoA 5) CoA is displaced by a phosphate group, which is transferred to GDP, forming GTP, a molecule with similar to ATP. GTP can also be used to generate ATP (Succinate is formed) 6) Two hydrogens are transferred to FAD, forming FADH2 and oxidizing Succinate to create Fumarate 7) Addition of a water molecule rearranges bonds in the substrate to Malate 8) Malate is oxidized, reducing NAD+ to NADH and regenerating oxaloacetate
C4 Plant Alternate Mode of Carbon Fixation Explained
1) An enzyme present only in mesophyll cells called PEP carboxylase adds CO2 to phosphoenolpyruvate (PEP), forming the four-carbon product oxaloacetate (PEP carboxylase has a much higher affinity for CO2 than does rubisco and has no addinity for O2) 2) Mesophyll cells export their four-carbon products (malate, in diagram) to bundle sheath cells through plasmodesmata 3) The four-carbon compounds release CO2, which is re-assimilated into organic material by rubisco in the Calvin cycle. This same reaction regenerates pyruvate, which is transported to mesophyll cells where ATP is used to convert pyruvate to PEP, allowing the reaction to continue. To generate this extra ATP, bundle-sheath cells carry out cyclic electric flow (only contain PS I)
Activation Independent of T cells (Proliferation of a B Cell Example (and diagram))
1) Antigens bind to the antigen receptors of only one of the three B cells shown 2) The selected B cell proliferates, forming a clone of identical cells bearing receptors for the antigen 3) Some daughter cells develop into long-lived memory cells that can respond rapidly upon subsequent exposure to the same antigen and other daughter cells develop into short-lived plasma cells that secrete antibodies specific for the antigen
ATP Synthase, a Molecular Mill
1) Hydrogen ions flowing down their gradient enter a half channel in a stator, which is anchored in the membrane 2) Hydrogen ions enter binding sites within a rotor, changing the shape of each subunit so that the rotor spins which the membrane 3) Each hydrogen ion makes one complete turn before leaving the rotor and passing through a second half channel in the stator into the mitochondrial matrix 4) Spinning of the rotor causes an internal rod to spin as well. This rod extends like a stalk into the knob below it, which is held stationary by part of the stator 5) Turning of the rod activates catalytic sties in the knob that produce ATP from ADP and Phosphate
Chemiosmosis Couples the Electron Transport Chain to ATP Synthesis
1) NADH and FADH2 shuttle high energy electrons extracted from food during glycolysis and the citric acid cycle in an electron transport chain built into the inner mitochondrial membrane. Electrons finally pass to oxygen at the "downhill" end of the chain, forming water. Most of the electron carriers of the chain are grouped into four complexes. Two mobile carriers, ubiquinone (Q) and cytochrone (Cyt c), move rapidly, ferrying electrons between the large complexes. As complexes I, III, and IV accept and then donate electrons, they pump protons from the mitchochondrial matrix into the intermembrane space. (In prokaryotes, protons are pumped outside the plasma membrane) Note that FADH2 deposits its electrons via complex II and so results in fewer protons being pumped into the intermembrane space than occurs with NADH. Chemical energy originally harvested from food is transformed into a proton-motive force, a gradient of H+ across the membrane 2) During Chemiosmosis, the protons flow back down their gradient via ATP synthase, which is built into the membrane nearby. The ATP synthase harnesses the proton-motive force to phosphorylate ADP, forming ATP. Together, electron transport and chemiosmosis make up oxidative phosphorylation
what are the functions of the kidney?
1. filter blood (& excrete waste through urine) 2. regulate blood volume and pressure 3. regulate concentrations of ions in blood 4. regulate extracellular ph 5. regulate red blood cell synthesis (via secretion of hormone erythropoietin) 6. regulate vitamin D synthesis
3 effects of Angiotensin 2
1. stimulate aldosterone secretion 2. vasoconstriction to increase bp 3. directly stimulates Na reabsorption in proximal tubule
b Level: 1
14. The major route of excretion for sodium ions (under normal conditions) is the A) skin. B) kidney. C) GI tract. D) adrenal cortex. E) sweat.
proximal and distal tubule
2 of the 3 main regions of the nephron
a Level: 2
21. Which of the following is most likely to happen to a group of students who relax by drinking a pitcher of their favorite beverage? A) an increase in urine volume B) an increase in urine osmolality C) an increase in ADH production D) increased aldosterone secretion E) a decrease in urine volume
c Level: 2
30. Oversecretion of aldosterone causes A) hyperkalemia. B) hypercalcemia. C) hypernatremia. D) increased urine volume. E) hyponatremia.
b Level: 2
32. Decreased extracellular potassium levels cause A) cells to become more excitable. B) hyperpolarization of cell membranes. C) more action potentials to be generated. D) increased permeability of cell membranes. E) hypopolarization of cell membranes.
b Level: 2
35. Oversecretion of aldosterone causes A) decreased secretion of calcium by the kidney. B) increased secretion of potassium by the kidney. C) decreased reabsorption of sodium by the kidney. D) increased reabsorption of phosphate ions by the kidney. E) decreased secretion of potassium by the kidney.
b Level: 2
36. Aldosterone secretion may be stimulated by A) ADH. B) elevated potassium levels. C) excess water intake. D) elevated sodium levels. E) low potassium levels.
e Level: 2
38. Which of the following will the body begin to do in order to compensate for hyperkalemia? A) vasoconstriction of blood vessels B) increase ADH secretion C) decrease aldosterone secretion D) increase the release of atrial natriuretic hormone E) increase aldosterone secretion
c Level: 1
39. Hyperkalemia is defined as A) excess excitability of kalems. B) reduction of plasma calcium level. C) increase in plasma potassium level. D) increase in plasma sodium level. E) decrease in plasma potassium level.
a Level: 1
41. Most of the calcium in the body is in the A) bones. B) plasma. C) kidneys. D) GI tract. E) extracellular fluid.
d Level: 2
42. In hypocalcemia, A) depolarization is prevented. B) PTH production is reduced. C) blood calcium levels are increased. D) neuromuscular excitability increases. E) neuromuscular excitability decreases.
D. low levels of calcium ion in the blood
5. What stimulates the release of PTH from the parathyroid gland? A. calcitonin from the anterior pituitary gland B. TSH from the posterior pituitary gland C. low levels of glucose in the blood D. low levels of calcium ion in the blood
a Level: 2
5. Which of the following people would be most severely affected by prolonged vomiting? A) 3-year-old male B) 15-year-old male C) 35-year-old male D) 35-year-old female E) 50-year-old male
% of body mass that is total body water
60%
c Level: 2
61. pH A) increases with acidity. B) is measured on a scale of 0 to 10. C) is a measure of the hydrogen ion concentration. D) reflects sodium content of body fluids. E) is not related to amounts of carbon dioxide in the body.
a Level: 1
63. Chemicals that function to minimize changes in the pH of body fluids are called A) buffers. B) inhibitors. C) accelerators. D) activators. E) stabilizers.
a Level: 2
64. If the hydrogen ion concentration in the blood increases, bicarbonate ions act as buffers by A) removing excess hydrogen ions from the plasma. B) releasing hydrogen ions into the plasma. C) dissociating into H+ and CO3-. D) combining with chloride ions. E) combining with hemoglobin.
d Level: 1
65. Which of the following is not a buffer system of the body? A) bicarbonate buffer system B) phosphate buffer system C) protein buffer system D) NaCl buffer system E) hemoglobin buffer
b Level: 2
66. Body fluid pH will rise dramatically when A) sodium is excreted by the kidney. B) large amounts of bicarbonate are ingested. C) carbonic acid is formed. D) the respiratory rate decreases. E) carbon dioxide levels increase.
d Level: 2
79. Respiratory alkalosis can occur as a result of A) asphyxia. B) asthma. C) severe emphysema. D) hyperventilation. E) hypoventilation.
An animal has a cardiac output of 40mL/min and a stroke volume of 5mL. What is its heart rate?
8 beats/minute. Cardiac Output = Heart Rate X Stroke Volume
b Level: 2
8. The predominant extracellular cation is A) bicarbonate. B) sodium. C) chloride. D) potassium. E) hydrogen ion.
Determine the rate of diffusion in the gas-exchange organ of an air-breathing animal where the area for gas exchange in the lung is 200 mm^2, the diffusion constant is 0.08, the PO2 of the air in the lung is 140mm Hg, the PO2 in blood flowing into the lung is 90mm Hg, and the thickness of the gas exchange membrane is 0.001mm.
800,000. (.08 x 200 x (140-90)/(.001))
b Level: 3
81. Which of the following regulatory mechanisms would be stimulated as a result of the increased osmolality that results from a Na+ level of 152 mEq/L? A) increased urine output B) an increased release of ADH C) an increase in renin production D) an increase in the secretion of aldosterone E) a decreased release of ADH
a Level: 3
84. Bob Trotts has an enteropathogenic E. coli infection resulting in severe diarrhea for 2 days. This could produce which of the following. 1. acidosis 2. alkalosis 3. increased respiration 4. decreased respiration 5. increased ADH secretion 6. increased renin secretion 7. increased urine concentration A) 1, 3, 5, 6, 7 B) 2, 4, 5, 6, 7 C) 1, 3, 6 D) 2, 4, 5, 7 E) 1, 4, 5, 7
e Level: 3
85. Azetazolamide (Diamox) is a diuretic. It functions by blocking the activity of carbonic anhydrase inside kidney tubule cells. This slows the formation of carbonic acid. By slowing the formation of hydrogen ions in the cells of the tubule, sodium reabsorption is also slowed. This results in the diuretic effect. Select from the following list the possible side-effects of Azetazolamide. 1. acidosis 2. reduced movement of bicarbonate ion into the plasma 3. an alkaline urine is produced 4. respiration increases A) 1, 4 B) 2, 3 C) 1, 2, 3 D) 2, 3, 4 E) 1, 2, 3, 4
47) The amino acid tyrosine is a starting substrate for the synthesis of A) epinephrine. B) steroid hormones. C) parathyroid hormone. D) vitamin D. E) acetylcholine.
A
urine production
A decrease in plasma osmolality would increase ADH production. plasma sodium levels. renin production. urine production.
Which of the following crosses lipid bilayers the slowest?
A sodium ion.
neutrophils
A type of white blood cell that engulfs invading microbes and contributes to the nonspecific defenses of the body against disease. Normally present in blood but not tissue Prominent compound of pus
12) Which of the following is true of ammonia? A) It is soluble in water. B) It can be stored as a precipitate. C) It has low toxicity relative to urea. D) Only A and C are true. E) A, B, and C are true.
A) It is soluble in water.
which 2 hormones are involved in regulating osmotic homeostasis in the body and blood pressure
ADH (vasopressin) and aldosterone
ADH and RAAS work together in maintaining osmoregulatory homeostasis through which of the following ways?
ADH regulates the osmolarity of the blood by altering renal reabsorption of water, and RAAS maintains the osmolarity of the blood by stimulating Na+ and water reabsorption.
How does ADH affect kidney?
ADH targets movement of aquaporin 2 channels from the cytosol of collecting duct cells to insert into the apical membrane (the one touching the lumen of the duct where urine is) so that water from urine flows through aquaporin, across collecting duct cell and through constitutively active aquaporin channels on the basal side into blood
A. glucocorticoids
Adrenal hormones useful in treating chronic inflammatory disorders such as rheumatism are A. glucocorticoids B. mineralocorticoids C. epinephrine D. norepinephrine
Which one of the following statements is NOT correct?
Aldosterone release decreases blood volume and blood pressure.
Select the correct statement about the immune system.
All antigen receptors produced by a single B cell or T cell are identical and bind to the same epitope.
Select the correct statement about osmoregulation. All osmoconformers are marine animals. All marine invertebrates are stenohaline. The less the gradient between an animal's internal osmolarity and its external osmolarity (that of its surroundings), the higher the cost of osmoregulation.
All osmoconformers are marine animals.
Which choice best describes an antigen?
An antigen is a foreign molecule that evokes a specific response by a lymphocyte.
How does an antihistamine reduce allergy symptoms?
An antihistamine blocks receptors for inflammatory chemicals released from granules within mast cells.
influence the same cell type that produced them
Autocrine chemical signals influence the same cell type that produced them. are secreted by some endocrine glands. have systemic effects. such as enkephalins may modulate the sensation of pain.
D. local hormones that act on the same cell that secreted them
Autocrines are A. neurohormones of the autonomic nervous system B. hormones that are circulating in the blood C. local hormones that act on neighboring cells D. local hormones that act on the same cell that secreted them
constriction of afferent and efferent arterioles.
Autoregulation in the kidney involves changes in the degree of constriction of afferent and efferent arterioles. sympathetic stimulation. aldosterone secretion. ADH secretion.
20) Hormones from the hypothalamus affect the release of all of the following except A) prolactin. B) oxytocin. C) growth hormone. D) thyroid-stimulating hormone. E) adrenocorticotropic hormone
B
44) Analysis of a blood sample from a fasting individual who had not eaten for 24 hours would be expected to reveal high levels of A) insulin. B) glucagon. C) secretin. D) gastrin. E) glucose.
B
51) In response to stress, the adrenal gland promotes the synthesis of glucose from noncarbohydrate substrates via the action of the steroid hormone A) glucagon. B) cortisol. C) epinephrine. D) thyroxine. E) ACTH.
B
61) Which of the following is not a category of endocrine gland stimulus? A) humoral B) hormonal C) neural D) enzyme
B
66) An example of antagonistic hormones controlling homeostasis is A) thyroxine and parathyroid hormone in calcium balance. B) insulin and glucagon in glucose metabolism. C) progestins and estrogens in sexual differentiation. D) epinephrine and norepinephrine in fight-or-flight responses. E) oxytocin and prolactin in milk production.
B
82) The major targets of growth hormone are ________. A) the blood vessels B) bones and skeletal muscles C) the liver D) the adrenal glands
B
Which statement best describes the difference in responses of effector B cells (plasma cells) and cytotoxic T cells?
B cells secrete antibodies against a virus; cytotoxic T cells kill virus-infected cells.
62) African lungfish, which are often found in small stagnant pools of fresh water, produce urea as a nitrogenous waste. What is the advantage of this adaptation? A) Urea takes less energy to synthesize then ammonia. B) Small stagnant pools do not provide enough water to dilute the toxic ammonia. C) The highly toxic urea makes the pool uninhabitable to potential competitors. D) Urea forms a precipitate and does not accumulate in the surrounding water. E) A buildup of urea in the blood makes a lungfish hypoosmotic to its environment.
B) Small stagnant pools do not provide enough water to dilute the toxic ammonia.
64) A clinical condition known as diabetes insipidus results in the production of large volumes of dilute urine. Which of the following is consistent with this condition? A) a high concentration of sodium in the urine B) very low production of ADH C) overproduction of ADH D) high production of aldosterone E) high production of angiotensin II
B) very low production of ADH
Two sister chromatids are joined at the centromere prior to meiosis. Which statement is correct?
Barring mutation, the two sister chromatids must be identical.
39) Proper functioning of the human kidney requires considerable active transport of sodium in the kidney tubules. If these active transport mechanisms were to stop completely, how would urine production be affected? A) No urine would be produced. B) A less-than-normal volume of hypoosmotic urine would be produced. C) A greater-than-normal volume of isoosmotic urine would be produced. D) A greater-than-normal volume of hyperosmotic urine would be produced. E) A less-than-normal volume of isoosmotic urine would be produced.
C) A greater-than-normal volume of isoosmotic urine would be produced.
37) Which of the following is not true concerning transport epithelia involved in water balance? A) One surface of the epithelium faces the outside environment directly or indirectly. B) The epithelium is a semipermeable barrier. C) The surface area is small, which prevents excessive water loss. D) The epithelium regulates the movement of solutes. E) Cells are joined by tight junctions.
C) The surface area is small, which prevents excessive water loss.
19) Which organism(s) has excretory organs known as Malpighian tubules? A) earthworms B) flatworms C) insects D) jellyfish E) both A and B
C) insects
4) Compared to the seawater around them, most marine invertebrates are A) hyperosmotic. B) hypoosmotic. C) isoosmotic. D) hyperosmotic and isoosmotic. E) hypoosmotic and isoosmotic.
C) isoosmotic.
Which hormone opposes the action of parathyroid hormone?
Calcitonin; Parathyroid hormone increases blood calcium levels; calcitonin lowers blood calcium levels
inhibiting the release of ADH from the posterior pituitary.
Consumption of alcohol increases urine production by decreasing the blood pressure. causing retention of sodium ions. inhibiting the release of ADH from the posterior pituitary. stimulating the release of aldosterone from the adrenals.
42) Which of the following has both endocrine and exocrine activity? A) the pituitary gland B) parathyroid glands C) salivary glands D) the pancreas E) adrenal glands
D
43) Linkage to membrane-bound receptor proteins on target cells activates the typical actions of the A) androgens. B) glucocorticoids. C) estrogens. D) pancreatic hormones. E) progestins.
D
62) Epinephrine is an example of A) an androgen. B) an estrogen. C) a progestin. D) a catecholamine. E) a glucocorticoid.
D
65) Which of the choices below is not a factor required for target cell activation by hormone receptor interaction? A) strength of the bond between the receptor and hormone B) blood levels of hormone C) number of receptors for that hormone D) type of hormone
D
76) The second-messenger mechanism of hormone action operates by ________. A) synthesizing more of the hormone than is actually needed B) not responding to a feedback mechanism C) increasing the basal metabolic rate in the target organ D) binding to specific receptors and employing the services of G proteins and cAMP
D
83) The parathyroid glands maintain adequate levels of blood calcium. This is accomplished through ________. A) blocking the action of growth hormone B) slowing the activity of tissues that require calcium for activity C) antagonizing the synthesis of calcitonin D) targeting the bone and activating osteoclasts so that calcium will be released
D
30) What substance is secreted by the proximal-tubule cells and prevents the pH of urine from becoming too acidic? A) bicarbonate B) salt C) glucose D) ammonia E) HCl
D) ammonia
micturition
Discharge of urine from the urinary bladder is called
Why use the endocrine system instead of the nervous system?
Endocrine: more gradual, systemic changes
Vertebrates have two major communication and control systems: the endocrine system and the nervous system. Choose the correct statement describing the coordination of these systems.
Epinephrine functions as a hormone in the endocrine system and as a neurotransmitter in the nervous system.
Both epinephrine and cortisol are involved in the body's response to stress. How do the two molecules differ?
Epinephrine mediates the short-term response; cortisol mediates the short- and long-term responses.
______, which is a short-term response to stress, is made by the ______.
Epinephrine; adrenal glands
) A sharp peak of leuteinizing hormone (LH) at the end of the follicular phase of the human menstrual cycle is caused by a buildup of
Estradiol
Which of the following hormones acts in the nucleus by binding to DNA?
Estradiol
) The ovaries produce
Estradiol and progesterone.
higher sodium content than intracellular fluid.
Extracellular fluid has a higher protein content than intracellular fluid. higher potassium content that intracellular fluid. higher sodium content than intracellular fluid. higher magnesium content than intracellular fluid
) During pregnancy, hemoglobin from the mother passes into fetal blood. (T,F) If the mother drinks an alcoholic beverage, alcohol passes from the mother's blood into fetal blood. (T,F)
F; T
True or false? The driving force for the unloading of oxygen from hemoglobin into tissues is the difference in PCo2 levels between the blood and body tissues.
False. The driving force for the diffusion of oxygen from hemoglobin into tissue sis the difference in PO2 levels between the blood (100mm Hg when oxygenated) and body tissues (40mm Hg at rest).
True or false? The circulatory system of land-dwelling vertebrates are composed of two pumping circuits: the systemic circulation, which is lower-pressure circuit to the lung, and the pulmonary circulation, which is a higher pressure circuit to the rest of the body.
False. The pulmonary circulation is the lower-pressure circuit to the lung, whereas the systemic circulation is the higher-pressure circuit to the rest of the body.
True or false? Lipid-insoluble hormones affect their target cells by binding to receptors inside the cell.
False; Lipid-insoluble hormones cannot cross the plasma membrane and get into the cell, so they must bind to receptors on the cell surface and transduce their signals through signal transduction pathways.
True or false? For a signal transduction pathway to be activated, hormones must be present in the bloodstream at very high concentrations.
False; Only low concentrations of hormones are needed in the bloodstream to activate a signal transduction pathway, which works by producing second messengers inside the cell that amplify the hormonal signal.
Which of the following nutrients contains the most energy per gram?
Fat (9 kcal of energy pre gram).
Ovaries
Female gonads
gaps between the podocyte processes in the visceral layer of Bowman's capsule.
Filtration slits is the name given to the points where the afferent arterioles enter the renal corpuscle. openings between the endothelial cells of the glomerular capillaries. gaps between the podocyte processes in the visceral layer of Bowman's capsule. basement membrane of the glomerular endothelium.
macrophages
Found within the lymph nodes, they are phagocytes that destroy bacteria, cancer cells, and other foreign matter in the lymphatic stream. Main phagocytles
Cells will usually divide if they receive the proper signal at a checkpoint in the _____ phase of the cell cycle.
G1
What type of interaction is directly responsible for the formation of secondary structure?
Hydrogen bonds between sections of the polypeptide backbone
A. Cushing's syndrome
Hypersecretion of glucocorticoids results in the following clinical symptoms: redistribution of body fat, hyperglycemia, osteoporosis, weakness, hypertension, 'moon face' and 'buffalo hump', excessive bruising, and poor wound healing. These symptoms are associated with A. Cushing's syndrome B. toxic goiter C. hyperparathyroidism D. Addison's disease
) Where are the two centers that control our hunger response located? The arcuate nucleus (ARC) is located in the ______. The nucleus tratus solitarious (NTS) is located in the _______.
Hypothalamus; base of the brain
) Anti-diuretic hormone (ADH) is synthesized in the ______. Erythropoietin (EPO) is synthesized in the ______.
Hypothalamus; kidneys
) Reproduction through parthenogenesis yields offspring who are genetically ______ to each other and ______ to the mother.
Identical; identical
Sweating-induced dehydration would have what effect on ADH secretion?
Increased ADH secretion.
Which trait would you expect to see in a lizard species living in the colder part of the range?
Increases fecundity/ This life history tends to invest more in quality rather than quantity.
(Relation to Fick's Law) Lungs increase the temperature of the air and are moist to allow greater solubility of gases.
Increasing k.
Which of the following increases the strength of the hydrophobic interactions in lipid bilayers and thus makes them less permeable to polar molecules?
Increasing length of the hydrocarbon chains.
3, 5, 1, 2, 4
Indicate the order in which urea molecules move to maintain the medullary concentration gradient. (1) ascending limb (2) distal convoluted tubule (3) interstitial fluid (4) collecting duct (5) descending limb 2, 5, 1, 4, 3 1, 3, 5, 2, 4 3, 5, 1, 2, 4 4, 2, 1, 3, 5
What would account for increased urine production as a result of drinking alcoholic beverages?
Inhibition of ADH secretion
a rapid fall in the blood sugar level.
Insulin shock occurs when there is damage to pancreatic beta cells. too much glucose available. a rapid fall in the blood sugar level. overstimulation of alpha cells.
In a healthy person, after a large meal, the production of _____ will increase. After fasting, the producton of ____ will increase.
Insuline; Glucagon
A behavioral physiologist is studying the homeostatic control of blood pH. In a trial, a lizard runs on a treadmill for a set amount of time and the blood pH is measured. The blood pH drops as carbon dioxide is released into the bloodstream. Which component of the homeostatic feedback system is responsible for deciding if the blood pH is far enough from normal that a response is necessary?
Integrator.
PLasmacytoid dendritic cells
Interferon factories - can produce grams of interferon into circulation.
What is the role of cAMP in the signal transduction pathway activated by epinephrine?
It binds to and activates protein kinase A, which then phosphorylates other enzymes; cAMP binds to and activates protein kinase A, which then phosphorylates other enzymes in the signal transduction pathway.
What is the function of a circulatory system?
It brings a transport liquid into close contact with all cells in the body.
What is rmax in a species like the giant panda?
It is low. Giant pandas have a low rate of increase for the population.
A primary reason that the kidneys have one of the highest metabolic rates of all body organs is that____
It operates an extensive set of active-transport ion pumps.
What is the function of the left ventricle?
It pumps oxygenated blood around the body via the systemic circulation.
accidental removal of the parathyroids during surgery
Julie was diagnosed with an aggressive tumor of the thyroid. Surgery was performed to remove the thyroid. However, post-operatively, Julie's blood calcium levels began declining to life-threatening levels. This decline is most likely due to thyroid hormone replacement therapy after the surgery. damage to the anterior pituitary during surgery. accidental removal of the parathyroids during surgery. improper laboratory handling of blood samples
Which pituitary secretion stimulates the testes to secrete androgens?
LH
From the pulmonary veins, blood flows to the ____.
Left atrium.
From the pulmonary veins, blood flows to the _____.
Left atrium.
Tissues are immunogically "typed" before an organ transplant to make sure that the donor and recipient match as closely as possible in their ___
MHC (major histocompatibility complex) proteins
correct
Mechanisms that regulate GFR work by adjusting blood flow into and out of the glomerulus and by altering the glomerular capillary surface area available for filtration.
Which of the following is an example of a negative feedback response? As the uterus contracts in labor and delivery, more oxytocin is released to intensify uterine contractions Meerkats bask in the sun in the cool mornings but avoid the sun during the heat of the day Sexual stimulation leads to sexual arousal nursing baby stimulates the release of oxytocin, which causes letdown of milk
Meerkats bask in the sun in the cool mornings but avoid the sun during the heat of the day
The plasma membrane of a neuron has voltage-gated sodium and potassium channels. What is the effect of membrane depolarization on these channels?
Membrane depolarization first opens sodium channels and then opens potassium channels.
How do memory cells differ from effector cells?
Memory cells live longer.
The response of the heating system reduces the stimulus. This is an example of ____ feedback.
Negative.
) The stress response is turned off by the elimination of stress, and by ______ feedback of cortisol to the ______.
Negative; hypothalamus
retention of hydrogen ions by the kidney
Once alkalosis has occurred, which of the following would you expect to happen? increased respiratory rate a plasma pH less than 7.40 retention of hydrogen ions by the kidney increased renal reabsorption of bicarbonate ions
protein
One difference between the plasma and interstitial fluid is that the plasma has significantly more _____ than interstitial fluid. protein bicarbonate chloride water volume
) When a primary oocyte undergoes meiosis, ______ are formed.
One egg and two polar bodies
Rank hemoglobins from most likely to bind to oxygen to most likely to release oxygen. *)1 bound oxygen PO2 100mm Hg *)3 bound oxygen PO2 40mm Hg *)3 bound oxygen PO2 100mm Hg *)1 bound oxygen PO2 40mm Hg
Order: Most likely to bind, most likely to release. 3 bound 100mm Hg, 1 bound 100mm Hg, 3 bound 40 mm Hg, 1 bound 40mm Hg
Select the correct statement about osmolarity. If two solutions are separated by a selectively permeable membrane, water flows by osmosis from a hyperosmotic solution to a hypoosmotic one. The contents of an animal cell are hyperosmotic. Osmolarity measures the moles of solute per liter of solution.
Osmolarity measures the moles of solute per liter of solution.
B. water
Reabsorption of sodium from the tubules of the nephron establishes an osmotic gradient that causes _____ to move back into the blood. A. salt B. water C. magnesium, D. calcium
Plasma Membrane
Receptors for nonsteroid hormones are located in association with a cell's _____ _____.
What would be the consequences if we were to reverse the direction of water flow over the gills of a fish, moving water inward past the operculum, past the gills, then out the mouth? This reversal of water flow would _____.
Reduce efficiency of gas exchange.
The micturition reflex
Relies on parasympathetic impulses from the micturition center in S2 and S3, results in contraction of the detrusor muscle, and inhibits motor neurons int he external urethral sphincter.
Which regions of the nephron function independently of hormonal control for the most part?
Renal corpuscle, proximal tubule, and loop of Henle.
occurs when the arterial PCO2 falls below 35 mmHg.
Respiratory alkalosis occurs when the arterial PCO2 falls below 35 mmHg. occurs when the arterial PCO2 is above 35 mmHg.
may inhibit reproductive functions
Secretions of the pineal body include vasopressin. may be involved with development of the may inhibit reproductive functions
The osmoregulatory process called secretion refers to the _____?
Selective elimination of excess ions and toxins from body fluids
How would a Oxygen saturation and PO2 in blood curve be different for a person who has lived atop a mountain for thousands of years?
Shifted to the left. Higher affinity for oxygen in the blood.
Which of the following correctly describes a difference between spermatogenesis and oogenesis?
Spermatogenesis results in four mature sperm cells, while oogenesis results in one mature egg cell.
How do steroid hormones differ from the polypeptide hormones and most amino-acid-derived hormones?
Steroids are lipid soluble and cross plasma membranes readily.
calcium levels
Stimulus for the secretion of parathyroid hormone is a decrease in serum potassium levels. calcium levels. calcitonin levels. phosphate levels
You open the window, and a blast of icy air enters the room. The temperature drops to 17 degrees Celsius, which acts as a _____ to the heating system.
Stimulus.
Which of the following occurs during meiosis but not during mitosis?
Synapsis occurs.
Adaptive immunity
Takes 4-7 days leaves immunological memory
Which of the following describes innate immunity?
Tears, saliva, and mucous secretions contain lysozyme, an enzyme that digests bacterial cell walls. Surface secretions from sebaceous and sweat glands give the skin an acidic pH that is unfavorable for bacterial colonization. Unbroken skin creates a physical barrier that cannot normally be penetrated by bacteria or viruses. Mucus traps microbes and other particles that come in contact with it.
Which of the following statements about the oxygen-hemoglobin interaction is true? 1) Each Hemoglobin molecule can bind one oxygen molecule. 2) The oxygen-hemoglobin dissociation curve is exponential, which means that hemoglobin can respond quickly to small changes in oxygen demand. 3) The binding of one oxygen molecule to hemoglobin stimulates the unloading of the oxygen molecules that are already bound. 4) The binding of one oxygen molecule to hemoglobin stimulates the binding of other oxygen molecules.
The binding of one oxygen molecule to hemoglobin stimulates the binding of other oxygen molecules.
Which statement about human reproduction is false?
The earliest stages of spermatogenesis occur closest to the lumen of the seminiferous tubules.
juxtaglomerular cells and the macula densa.
The juxtaglomerular apparatus is composed of juxtaglomerular cells and the macula densa. podocytes and juxtaglomerular cells. the macula densa and the filtration membrane. juxtaglomerular cells and the filtration membrane.
the blood pressure in the afferent arteriole decreases.
The kidneys produce renin when the urine becomes acidic. the peritubular capillaries dilate. the blood pressure in the afferent arteriole decreases. sodium chloride concentration in the distal tubule increases
kidney.
The major route of excretion for sodium ions (under normal conditions) is the skin. kidney. GI tract. adrenal cortex
Select the correct statement describing the osmolarity of mammalian urine. The osmolarity of mammalian urine may vary over time. The osmolarity of mammalian urine varies little between species Mammalian urine is always hyperosmotic to blood.
The osmolarity of mammalian urine may vary over time.
The posterior pituitary is anatomically and developmentally an extension of the hypothalamus. Which of the following is a true statement about the posterior pituitary?
The posterior pituitary's hormones are actually produced in neurosecretory cells that originate in the hypothalamus.
Which arrow is disrupted in individuals with type 2 diabetes mellitus?
The top black arrow converting glucose to glycogen. Type 2 diabetes can produce insulin, but have defective receptors for it.
neurohypophysis and adenohypophysis.
The two functional portions of the pituitary gland are the infundibulum and neurohypophysis. pars nervosa and pars tuberalis. neurohypophysis and adenohypophysis. adenohypophysis and infundibulum.
What did studies of the bridled goby, a coral-reef fish, and song sparrows of Mandarte island demonstrate?
There is a strong density-dependent relationship in survivorship. When population density is high, mortality rates are also high relative to fecundity.
True or false? The basic functions of the human female reproductive system are to produce eggs, develop offspring, and make hormones.
True
True or false? The homeostatic system for blood calcium concentration is maintained by the hormones calcitonin and parathyroid hormone.
True
True or false? The pancreas is responsible for producing hormones that maintain the homeostatic levels of glucose in the blood.
True
Sharks live in seawater. Their tissues are isotonic to seawater,but their concentrations of sodium ions, potassium ions, and chloride ions in cells and extracellular fluids are similar to those of freshwater fishes. How is that possible?
Urea and trimethylamine oxide contribute to intra- and extracellular osmolarity in shark tissues.
Order in water requirements from least to greatest Ammonia Uric Acid Urea
Uric Acid < Urea < Ammonia
peristaltic contractions
Urine flows through the ureters to the bladder as the result of gravity. a pressure gradient. a concentration gradient. peristaltic contractions.
all of the above
Urine formation involves filtration of the plasma. reabsorption from the filtrate. secretion into the filtrate. all of the above
ureter.
Urine is carried from the kidneys to the urinary bladder by the urethra. ureter. calyces. renal columns.
osmosis
Water moves back and forth across the plasma membrane by the process of osmosis. filtration. diffusion. active transport.
insulin secretion decreases; glucagon secretion increases.
When blood sugar levels decrease, insulin and glucagon secretion increase. insulin and glucagon secretion decrease. insulin secretion increases; glucagon secretion decreases. insulin secretion decreases; glucagon secretion increases
Which of the following is an example of negative feedback? 1) During birthing contractions, oxytocin is released and acts to stimulate further contractions. 2) After a blood vessel is damaged, signals are released by the damaged tissues that activate platelets in the blood. These activated platelets release chemicals that activate more platelets. 3) When the level of glucose in the blood increases, the pancreas produces and releases the hormone insulin. Insulin acts to decrease blood glucose. As blood glucose decreases, the rate of production and release of insulin decreases as blood glucose decreases. 4) When a baby is nursing, suckling leads to the production of more milk and a subsequent increase in the secretion of prolactin.
When the level of glucose in the blood increases, the pancreas produces and releases the hormone insulin. Insulin acts to decrease blood glucose. As blood glucose decreases, the rate of production and release of insulin decreases as blood glucose decreases.
Which of the following is an example of negative feedback? 1) After a blood vessel is damaged, signals are released by the damaged tissues that activate platelets in the blood. These activated platelets release chemicals that activate more platelets. 2) During birthing contractions, oxytocin is released and acts to stimulate further contractions. 3) When a baby is nursing, suckling leads to the production of more milk and a subsequent increase in the secretion of prolactin. 4) When the level of glucose in the blood increases, the pancreas produces and releases the hormone insulin. Insulin acts to decrease blood glucose. As blood glucose decreases, the rate of production and release of insulin decreases as blood glucose decreases
When the level of glucose in the blood increases, the pancreas produces and releases the hormone insulin. Insulin acts to decrease blood glucose. As blood glucose decreases, the rate or production and release of insulin decreases as blood glucose decreases.
A. parathyroid gland
Which endocrine gland is NOT regulated by tropic hormones of the anterior pituitary? A. parathyroid gland B. thyroid gland C. adrenal cortex D. ovaries
C. glycosuria, polyuria, ketosis, and hyperglycemia
Which of the following are associated with diabetes mellitus? A. premature closing of the epiphyseal plates B. massive enlargement of the thyroid gland C. glycosuria, polyuria, ketosis, and hyperglycemia D. exophthalmos, gynecomastia, and buffalo hump
Large glomerular capillary surface, high glomerular capillary pressure and mesangial cells regulating the filtering surface area
Which of the following are features of the renal corpuscle that enhance its filtering capacity?
all of these
Which of the following helps maintain a high solute concentration in the kidney medulla? high urea concentration in medulla active transport of solutes from ascending limb the vasa recta all of these
Epinephrine increases blood pressure
Which of the following is true? The effects of epinephrine are long-lasting (days to weeks). Epinephrine increases blood pressure. Epinephrine decreases heart rate. Epinephrine increases GI tract activity.
increased numbers of active transport molecules for glucose
Which of the following occurs when insulin molecules bind to their receptors on target cells? increased mRNA synthesis in the target cells minimal uptake of glucose by target cells phosphorylation of proteins in the nuclear membrane in the target cells increased numbers of active transport molecules for glucose
decreases
_____ as it flows up the ascending limb, and continue to decrease as it flows through the rest of the nephron and collecting duct.
The response to a lipid soluble hormone is usually
a change in gene expression
Portal blood vessels connect two capillary beds found in the Select one: a. hypothalamus and anterior pituitary. b. posterior pituitary and thyroid gland. c. anterior pituitary and adrenal gland. d. hypothalamus and thalamus. e. anterior pituitary and posterior pituitary
a. hypothalamus and anterior pituitary.
The anterior and posterior lobes of the pituitary differ in that Select one: a. many anterior pituitary hormones regulate other endocrine glands whereas posterior pituitary hormones regulate nonendocrine tissues b. the anterior lobe of the pituitary is nervous tissue that connects directly to the brain whereas the posterior pituitary is derived from non-neural tissues c. the posterior pituitary gland synthesizes oxytocin and antidiuretic hormone (ADH) whereas the anterior lobe receives all of its hormone products in the blood d. the anterior lobe of the pituitary receives neuronal impulses from brain cells whereas the posterior lobe receives blood-borne hormones e. the posterior lobe of the pituitary operates independently of the brain whereas the anterior lobe is directly dependent on brain activity
a. many anterior pituitary hormones regulate other endocrine glands whereas posterior pituitary hormones regulate nonendocrine tissues
An inhibitory postsynaptic potential (IPSP) occurs in a membrane made more permeable to Select one: a. potassium ions correct b. calcium ions. c. all neurotransmitter molecules d. ATP e. sodium ions
a. potassium ions
Testosterone is an example of a chemical signal that affects the very cells that synthesize it, the neighboring cells in the testis, along with distant cells outside the gonads. Thus, testosterone is an example of
an autocrine signal, a paracrine signal, and an endocrine signal.
Insufficient dietary iodine leads to
an enlarged thyroid gland, called a goiter
Estradiol is an example of
an estrogen
A decrease in the volume of urine excreted would be expected following
an increase in aquaporin channels in collect duct
Seen in section, the kidney is divided into...
an outer cortex and an inner medulla
The number of completed meiosis II that a human female experiences during her lifetime is equal to Select one: a. The number of oocytes she produces b. The number of fertilizations (= conceptions) she experiences c. The number of menstrual cycles she experiences over her lifetime d. The number of children she gives birth to
b. The number of fertilizations (= conceptions) she experiences
The observation that the acetylcholine released into the junction between a motor neuron and a skeletal muscle binds to a sodium channel and opens it is an example of Select one: a. a second-messenger-gated sodium channel b. a ligand-gated sodium channel. c. a voltage-gated potassium channel d. a voltage-gated sodium channel. e. a chemical that inhibits action potentials.
b. a ligand-gated sodium channel.
For a neuron with an initial membrane potential at -70 mV, an increase in the movement of potassium ions out of that neuron's cytoplasm would result in Select one: a. the depolarization of the neuron. b. the hyperpolarization of the neuron. c. the replacement of potassium ions with calcium ions. d. the replacement of potassium ions with sodium ions.
b. the hyperpolarization of the neuron. correct
skeletal system functions
body support, protection of internal organs, movement
In correct chronological order, the three phases of the human uterine cycle are Select one: a. follicular → ovulation → luteal b. follicular → luteal → secretory. c. menstrual → proliferative → secretory. d. proliferative → luteal → ovulation
c. menstrual → proliferative → secretory.
The human knee-jerk reflex requires an intact Select one: a. hypothalamus b. medulla c. spinal cord. d. cerebellum e. corpus callosum
c. spinal cord.
Angiotensin II is a potent hormone that...
causes constriction of the efferent arteriole at the nephron, triggers the release of ADH in the CNS, stimulates secretion of aldosterone by the adrenal cortex and epinephrine by the adrenal medulla
cytokines
chemicals released by the immune system that attack infections and communicate with the brain to elicit anti-illness behaviors IS a hormone that is named after a immunologist
Which of these molecules is incorrectly paired with a source?
chemokines - cytotoxic T cell
aldosterone is synthesized from what precursor
cholesterol
Name that tissue: Blood
connective
nervous system functions
coordination of body activities; detection of stimuli and formulation of responses to them
endocrine system functions
coordination of body activities; digestion and metabolism
epithelial tissue
covers outside of body and lines organs and cavities; barrier against mechanical injury, pathogens, fluid loss, active interfaces with environment
HIV targets include all of the following except
cytotoxic T cells.
The hormone epinephrine causes opposite effects in two populations of target cells because Select one: a. the chemical form of epinephrine released by neurons is different from the epinephrine released by endocrine cells b. epinephrine activates biochemical pathways in one set of target cells but works only by changing gene expression in the other set of target cells c. epinephrine crosses the membrane on one set of target cells but binds to membrane-bound receptors in the other set of target cells d. each set of target cells has different receptor-transduction mechanisms e. epinephrine can only reach target cells in adipose tissue, as it is fat-soluble
d. each set of target cells has different receptor-transduction mechanisms
A bone marrow transplant may not be appropriate from a given donor (Jane) to a given recipient (Jane's cousin Bob), even though Jane has previously given blood for one of Bob's needed transfusions, because Select one: a. Jane's class II genes are not expressed in bone marrow. b. for each gene, there is only one blood allele but many tissue alleles. c. a blood type match is less stringent than a match required for transplant because blood is more tolerant of change d. even though Jane's blood type is a match to Bob's, her MHC proteins may not be a match. e. Bob's immune response has been made inadequate before he receives the transplant.
d. even though Jane's blood type is a match to Bob's, her MHC proteins may not be a match.
Labor contractions can be increased by the medical use of a synthetic drug that mimics the action of Select one: a. luteinizing hormone. b. prolactin c. vasopressin d. oxytocin
d. oxytocin
In the communication between a motor neuron and a skeletal muscle Select one: a. action potentials are possible on the skeletal muscle but not the motor neuron. b. the motor neuron fires action potentials but the skeletal muscle is not electrochemically excitable. c. the motor neuron is considered the postsynaptic cell and the skeletal muscle is the presynaptic cell. d. the motor neuron is considered the presynaptic cell and the skeletal muscle is the postsynaptic cell
d. the motor neuron is considered the presynaptic cell and the skeletal muscle is the postsynaptic cell correct
Drinking a lot of water will reduce blood osmolarity and trigger ____ ADH secretion, leading to ____ reabsorption of water in the collecting ducts of the kidney.
decreased, decreased
The portion of the renal segment that is under aldosterone stimulation is the...
distal convoluted tubule
The primary site for secretion of substances into the filtrate is the...
distal convoluted tubule
If a portion of the pancreas is surgically removed from a rat and the rat subsequently loses its appetite, one explanation is that the removed portion contains cells that secrete a chemical signal that somehow stimulates appetite. Given this scenario, what type of chemical signaling is occurring?
endocrine
aldosterone
enhances activity of sodium-potassium pumps in basolateral membrane and Na_ channels in apical membrane of principal cells in collecting duct
Sperm become capable of movement while in the _____.
epididymis
What hormone is responsible for the "fight or flight" response to danger?
epinephrine and norepinephrine
Which of these hormones are responsible for the "fight or flight" response to danger?
epinephrine and norepinephrine
Which of these is a nonsteroid hormone?
epinephrine and oxytocin
which of these is a nonsteroid hormone? estrogen testosterone both estrogen and testosterone oxytocin epinephrine and oxytocin
epinephrine and oxytocin
A chemical signal that has both endocrine and neural roles is
epinephrine.
The amino acid tyrosine is a starting substrate for the synthesis of
epinephrine.
During the menstrual cycle, ________ peaks first, ________ peak next, and finally ________ surges.
estradiol; LH and FSH; progesterone
What of the extracellular signal molecules could diffuse through a plasma membrane and bind to an intracellular receptor?
estrogen
Developing ovarian follicles primarily secrete _____.
estrogens
juxtamedullary nephrons
extend deep into the medulla; essential for production of urine that is hypeosmotic to body fluids
Prostaglandins are local regulators whose chemical structure is derived from
fatty acids
In pine, the embryo develops within the _____.
female gametophyte
During the Carboniferous period, forests consisting mainly of _____ produced vast quantities of organic matter, which was buried and later became coal.
ferns and other seedless plants
What process in the nephron is least selective? a. secretion b. salt pumping by the loop of Henle c. Reabsorption d. Filtration e. active transport
filtration
Which process in the nephron is LEAST selective?
filtration
Which process in the nephron is least selective?
filtration
Which process in the nephron is least selective? filtration salt pumping by the loop of Henle secretion reabsorption active transport
filtration
For what purpose(s) might a karyotype be prepared?
for prenatal screening, to determine if a fetus has the correct number of chromosomes to determine whether a fetus is male or female to detect the possible presence of chromosomal abnormalities such as deletions, inversions, or translocations
fibrous connective
found in tendons and ligaments
The thin segments in the loop of Henle are...
freely permeable to water; relatively impermeable to ions and other solutes
Kidneys, the excretory organs of vertebrates
function in both excretion and osmoregulation
Osmoregulation in marine fish
gain of water and salt ions from food through mouth; excretion of salt ions from gills; osmotic water loss through gills and other parts of body surface; excretion of salt ions and small amounts of water in scanty urine from kidneys
Many marine and freshwater bony fish achieve osmoregulation via
gain of water through food.
bone
hard mineral of calcium, magnesium, and phosphate ions in a matrix of collagen
Endocrine glands that are sources of steroid hormones
have a very short latency between steroid synthesis and steroid release.
how does ADH secretion affect urine excretion
high ADH decreases Urine output and increases urine concentration
hyperaldosteronism
high aldosterone production leading to 1. low serum K/H --> hypokalemia and alkalosis 2. suppressed plasma renin activity 3. high bp 4. initial increase in Na--> increase ANP neg feedback --> normal Na levels
The counter current multiplier system in the nephrons of mammalian kidneys allows the development of a concentration gradient of salt and urea in the medullary fluid that is
high enough to develop hyper osmotic urine
Among insects, the metamorphic transition from pupal form to adult form is associated with _____.
high levels of ecdysteroids and reduced levels of juvenile hormone; The ecdysteroids are produced by the prothoracic gland and the juvenile hormone is secreted by the corpora allata.
Movement is driven by the
high osmolarity of the interstitial fluid, which is hyper osmotic to the filtrate
blood vessels and nerves enter the kidney at?
hilum
The way this heating system maintains a stable room temperature is similar to the way an animal's body controls many aspects of its internal environment. The maintenance of a relatively constant internal environment is known as
homeostasis
Two antagonistic hormones regulate the
homeostasis of calcium (Ca2+) in the blood of mammals
anterior pituitary
hormonal signals from the hypothalamus trigger the synthesis and release of hormones from here; these hormones regulate other endocrine glands
The corpus luteum is retained upon fertilization due to the presence of which hormone?
human chorionic gonadotropin (hCG)
Human urine is usually more acidic than most other body fluids because
hydrogen ions are actively moved into the filtrate.
filtration
hydrostatic pressure drives this; the excretory tubule collects a filtrate from the blood. water and solutes are forced by blood pressure across the selectively permeable membranes of a cluster of capillaries and into the excretory tubule
Marine bony fishes are
hypo osmotic compared with their environment; their kidneys have small glomeruli and some lack glomeruli entirely; filtration rates are low, and very little urine is excreted
Which of the following is the most likely explanation for hypothyroidism in a patient whose iodine level is normal?
hyposecretion of TSH
What gland secretes releasing hormones?
hypothalamus
innate immunity
immunity to disease that occurs as part of an individual's natural biologic makeup Kicks in very rapodily and no emmory after infection is over
Type 1 diabetes mellitus (insulin-dependent)
in an autoimmune disorder
Predict the effects of a drug that increases adrenocorticotropic hormone (ACTH) synthesis.
increase in glucocorticoid production
aldosterone
increased angiotensin II level and increased level of plasma K+ promote release of this enzyme by adrenal cortex
The results of the effect of aldosterone along the DCT, the collecting tubular and the collecting duct are...
increased conservation of sodium ions and water
anitdiuretic hormone (ADH)
increased osmolarity of extracellular fluid or decreased blood volume promotes release of this hormone from the posterior pituitary gland
anitdiuretic hormone (ADH)
increases facultative reabsorption of water, which decreases osmolarity of body fluids
action of V2 receptor is...
increases insertion and expression of aquaporin 2 channels in kidney collecting duct cells
aldosterone
increases secretion of K+ and reabsorption of Na+, Cl-; increases reabsorption of water, which increases blood volume
rapid effect of aldosterone binding to receptor
induces expression of SGK1 which prevents degradation of any subunit alpha already synthesized (this interaction is mediated by insulin binding) SGK1 also stimulates Na/K pump
Excretory organs known as Malpighian tubules are present in
insects
Type 2 diabetes mellitus (non-insulin-dependent)
insulin deficiency, reduced response of target cells due to change in insulin receptors
Hypothalamus
integrates nervous and endocrine systems; synthesizes oxytocin and ADH; synthesizes some hormones that are released into blood vessels bound for another gland
The transfer of fluid from the glomerulus to Bowman's capsule___.
is mainly a consequence of blood pressure force-filtering the fluid.
The transfer of fluid from the glomerulus to Bowman's capsule
is mainly a consequence of blood pressure in the capillaries of the glomerulus.
Compared to the seawater around them, most marine invertebrates are___.
isoosmotic
Osmoconformeers are
isoosmotic with their surroundings and do not regulate their osmolarity
Compared to the seawater around them, most marine invertebrates are
isoosmotic.
The body fluids of an osmoconformer would be ________ with its ________ environment.
isoosmotic; saltwater
how is aquaporin 2 different from other aquaporins?
it is not constitutively present but it under hormonal regulation (by ADH!)
A primary reason that the kidneys have one of the highest metabolic rates of all body organs is that it is the body's only means of shedding excess nutrients. it operates an extensive set of active-transport ion pumps. it has an abundance of myogenic smooth muscle. it stores the body's excess fats. it has membranes of varying permeability to water.
it operates an extensive set of active-transport ion pumps.
A necropsy (postmortem analysis) of a marine sea star that died after it was mistakenly placed in fresh water would likely show that i died because___.
it was so hypertonic to the fresh water that it could not osmoregulate.
A drop in blood pressure near the glomerulus causes the
juxtaglomerular apparatus (JGA) to release the enzyme renin
Which one of the following structures is found only in birds and mammals and NOT in other vertebrates?
juxtamedullary nephrons
Fick's law of diffusion describes the factos that influence the diffusion of respiratory gases across biological membranes like gills and lungs. Diffusion rate= k x A x (P2-P1)/D. Natural selection is LEAST likely to act upon which variable in Fick's law?
k.
at what level is aldosterone regulated
level of enzyme/production of steroid (steroids are not stored, they are secreted immediately)
Emotion, motivation, olfaction, behavior, and memory, in humans, are mediated by the _____.
limbic system
In their mechanism of action, a difference between lipid-soluble and water-soluble hormones is that _____.
lipid-soluble hormones bind to an intracellular receptor and this hormone-receptor complex binds to DNA
In their mechanism of action, a difference between lipid-soluble and water-soluble hormones is that _____.
lipid-soluble hormones bind to an intracellular receptor and this hormone-receptor complex binds to DNA; Most water-soluble signals bind to plasma membrane proteins, initiating signal-transduction pathways. In contrast, the lipid-soluble hormones enter target cells and bind with intracellular receptors; the hormone-receptor complexes act as transcription factors, thus altering gene expression.
Urea is produced in the
liver from NH3 and CO2.
In which region of the nephron is a steep osmotic gradient created?
loop of Henle
The proximal convoluted tubule (PCT) and the distal convoluted tubule (DCT) are separated by a U-shaped tube called the...
loop of Henle
calcitonin
lowers blood calcium level
set point
maintaining a variable, such as body temperature or solute concentration, at or near a particular value
homeostasis is the
maintenance of a relatively constant and optimal internal environment
The collecting system in the kidney is responsible for...
making final adjustments to the sodium ion concentration and volume of urine
What can alter thyroid function
malnutrition
Asexual reproduction results in offspring that are genetically identical to their parent. What type of cell division occurs to generate this type of offspring?
mitosis
As filtrate moves down the loop of Henle, the surrounding interstitial fluid becomes____ concentrated than the filtrate, so____leaves the filtrate
more...water
Releasing and inhibiting hormones secreted by the ___ regulate hormones released by the ____
Hypothalamus, anterior pituitary
Hormone cascade pathway
a hormone can stimulate the release of a series of other hormones, the last hormone in the pathway activates a non endocrine target cell
What hormone promotes water retention by the kidneys?
antidiuretic hormone (ADH)
All three sex hormones are found in
both males and females, but in significantly different proportions
What hormone opposes the action of parathyroid hormone?
calcitonin
Adrenocorticotropic hormone (ACTH) triggers the release of____in response to stress
glucocoticoids
The heater turns on, and the temperature in the room____ until it returns to the original setting.
increases
How do non steroid hormones differ from steroid hormones?
non steroid hormones act via signal transduction pathways; a steroid hormones do not act via signal transduction pathways
What hormone stimulates milk production?
prolactin
The hormone enters target cells and binds to
protein receptors in the cytoplasm or nucleus
Aldosterone produced by the adrenal glands control the
reabsorption of sodium ions by the kidneys
Lipid-soluble hormones
steroid hormones; pass easily through cell membranes
You open the window, and a blast of icy air enters the room. The temperature drops to 17 degrees Celsius, which acts as a_____ to the heating system
stimulus
The role of the pancreas as an endocrine gland that mediates glucose homeostasis is of great importance to health, but a patient whose pancreas has been surgically removed also loses
the body's source of most of its digestive enzymes
In a simple neuroendocrine pathway
the stimulus is received by a sensory neuron; the neuron stimulates a neurosecretory cell; the neurosecretory cell secretes a neurohormone; the neurohormone enters the bloodstream and travels to target cells
Fuels
- Compounds that can participate in exergonic reactions - Some of the energy taken out of chemical storage can be used to do work; the rest is dissipated as heat
Phytochemicals
- Compounds with antioxidant properties - Plants can synthesize all the antioxidants they require, but humans and other animals must obtain some of them from their diets
PS II
- Reaction center chlorophyll a of photosystem II is known as P680 because this pigment best absorbs light with a wavelength of 680 nm (red part of spectrum)
Primary Electron Acceptor
- Reaction-center complex contains a molecule capable of accepting electrons and being reduced
what other hormone besides aldosterone is a good ligand for the mineral corticoid receptor?
Cortisol
The simplest hormone signaling pathway (the endocrine pathway) is
(1) A stimulus causes an endocrine cell to release a hormone. (2) The hormone acts on an effector cell. (3) The effector cell generates a response. This system is used in animals, but not often.
A neuroendocrine pathway is
(1) A stimulus causes a receptor to transmit a neural signal to neurons in the central nervous system (CNS). (2) A cell in the CNS releases a hormone (a neuroendocrine signal in Fig. 47.2b). (3) The hormone acts on an effector cell. (4) The effector cell generates a response. The only difference between an endocrine and neuroendocrine is that the endocrine is released by an ordinary cell, and a neuroendocrine is released by a nerve cell.
Hormone X activates the cAMP second messenger system in its target cells. The greatest response by a cell would come from
) applying a molecule of hormone X to the extracellular fluid surrounding the cell.
Fermentation (general)
- A catabolic process that causes a partial degradation of sugars or other organic fuel that occurs without the use of oxygen or an electron transport chain - An extension of glycolysis that allows continuous generation of ATP by the substrate-level phosphorylation of glycolysis - Must have a sufficient supply of NAD+ so there are reactions that regenerate NAD+ by transferring electrons from NADH to pyruvate or derivatives of pyruvate - NAD+ can be reused to oxidize sugar by glyclolysis which nets two ATP by substrate level phosphorylation - Aerobic repsiration yields up to 16 times as much ATP per glucose as does fermentation
Adaptation of Hibernating Animals
- Brown fat, is made up of cells packed full of mitochondria, the inner mitochondrial membrane contains a channel protein (the uncoupling protein) which allows protons to flow back down their concentration gradient without generating ATP - Activation of these proteins in hibernating mammals results in ongoing oxidation of stored fuel (fats), generating heat without any ATP production
Immunodeficiency Diseases
- A disorder in which an immune system response to antigens is defective or absent - An inborn immunodeficiency results from a genetic or developmental defect in the immune system (results from defects in the production of specific proteins, such as antibodies or the proteins of the complement system, depending on the specific genetic defect--either innate or adaptive defenses or both may be impaired) - In severe combined immunodeficiency SCID, functional lymphocytes are rare or absent, lacking an adaptive immune response, SCID patients are susceptible to infections (i.e. pneumonia, meningitis) that can cause death in infancy (treatments include bone marrow and stem cell transplantation) - An acquired immunodeficiency develops later in life following exposure to chemical or biological agents - An immunodeficiency can lead to frequent and recurrent infections and increased susceptibility to certain cancers - Certain cancers also suppress the immune system, especially Hodgkin's disease (which damages the lymphatic system)
ATP Synthase
- A many copied protein complex that populates the inner membrane of the mitochondrion or the prokaryotic plasma membrane - It is the enzyme that actually makes ATP from ADP and inorganic phosphate - Works like an ion pump running in reverse - ATP synthase uses the energy of an existing ion gradient to power ATP synthesis - Power source is a difference in the concentration of H+ on opposite sides of the inner mitochondrial membrane (can also think of it as a difference in pH) - Multisubunit complex with four main parts, each made up of multiple polypeptides - Protons move one by one into binding sites on one of the parts (rotor), causing it to spin in a way that catalyzes ATP production from ADP and inorganic phosphate - Smallest molecular rotary motor known in nature
Recognition of Protein Antigens by T Cells Begins When
- A pathogen or part of a pathogen either infects or is taken in by a host cell - Inside the host cell, enzymes in the cell cleave the antigen fragment, then binds to an MHC molecule in side the cell - Movement of the MHC molecule and bound antigen fragment to the cell surface results in antigen presentation (the display of the antigen fragment in an exposed groove of the MHC protein) - If the cell displaying an antigen fragment encounters a T cell with the right specificity , the T cell receptor can bind to both the antigen fragment and the MHC molecule (this binding is important because it enables a T cell to participate in an adaptive immune response) - Proliferation follows
Spectrophotometer
- Ability of a pigment to absorb various wavelengths of light can be measured by this - Machine directs beams of light of different wavelengths through a solution of the pigment and measures the fraction of the light transmitted at each wavelength
Importance of Photosynthesis
- About 50% of the organic material made by photosynthesis is consumed as fuel for cell respiration in the mitochondria of plant cells - Sometimes there is a loss of photosynthetic products by photorespiration - Green cells are the only autotrophic parts of the plant - Rest of plant depends on organic molecules exported from leaves via veins (in most plants, carbohydrate is transported out of leaves in the form of sucrose) - After arriving at nonphotosynthetic cells, the sucrose provides raw material for cell respiration and a multitude of anabolic pathways that synthesize proteins and lipids, etc - Considerable amount of sugar in the form of glucose is linked together to make the polysaccharide cellulose (especially in plant cells that are growing and maturing) - Cellulose, the main ingredient of cell walls, is the most abundant organic molecule in the plant--and probably on the surface of the planet - Plants stockpile extra sugar by synthesizing starch, storing some in the chloroplasts and some in storage cells of roots, tubers, seeds, and fruits (must remember that many plants lose leaves, roots, stems, and fruits) - Photosynthesis is responsible for the presence of oxygen in our atmosphere - Photosynthesis makes an estimated 1.1 tons of carbohydrate per year (no other chemical process on the planet can match the output of photosynthesis)
Evasion of Innate Immunity by Pathogens
- Adaptations have evolved in some pathogens that enable them to avoid destruction by phagocytic cells - Example: The outer capsule that surrounds certain bacteria interferes with molecular recognition and phagocytosis
Latency
- After infecting a host, some viruses enter a largely inactive state called latency - Dormant viruses cease making most viral proteins and typically produce no free virus particles and do not trigger an adaptive immune response - Nevertheless, the viral genome persists in the nuclei of infected cells, either as a separate small DNA molecule or as a copy integrated into the host genome - Latency typically persists until conditions arise that are favorable for viral transmission or unfavorable for host survival (i.e. when a host is infected by another pathogen) - These circumstances trigger the synthesis and release of virus particles that can infect new hosts
Innate Immunity (general)
- All animals (and plants) have innate immunity - It is a defense that is active immediately upon infection - The same whether or not the pathogen has been encountered previously - Includes an outer covering (such as skin or a shell) that provides a significant barrier to entry by microbes - Has chemical secretions that trap or kill microbes that guard the body's entrances and exits (linings of the digestive tract, airway, and other exchange surfaces provide additional barriers to infection) - For vertebrates, it serves both as an immediate defense against infection AND as the foundation for adaptive immune defenses
Chloroplast Location
- All green parts of a plant, including green stems and unripened fruit, have chloroplasts - Leaves are the major sites of photosynthesis in most plants (approx. half a million chloroplasts in a chunk of leaf with a top surface area of 1mm^2) - Mainly found in the cells of the mesophyll (tissue in the interior of the leaf, typical mesophyll cell has about 30-40 chloroplasts, each organelle measuring about 2-4µm by 4-7µm)
Three Types of Pigments in Chloroplasts
- Chlorophyll a - Chlorophyll b (accessory pigment) - Carotenoids (group of accessory pigments)
Basic Pathway of Electron Transport
- Collection of molecules embedded in the inner membrane of the mitochondrion in eukaryotic cells (in prokaryotes, these molecules reside in the plasma membrane) - Folding of in the inner membrane to cristae increases its surface area (providing space for thousands of copies of the chain in each mitochondrion) - Most components are proteins which exist in multi-protein complexes (tightly bound to these proteins are prosthetic groups: non protein components essential for the catalytic functions of certain enzymes) - Each component of the chain becomes reduced when it accepts electrons from its "uphill" neighbor; it then returns to its oxidized form as it passes electrons to its "downhill" neighbor
Allergens
- Allergies are exaggerated (hypersensitive) responses to certain antigens called allergens - Most common allergies involve antibodies of the IgE class - Hay Fever occurs when plasma cells secrete IgE antibodies specific for antigens on the surface of pollen grains - Some IgE antibodies attach by their base to mast cells in connective tissues - Pollen grains that enter the body later attach to the antigen-binding sites of these IgE antibodies - This attachment links adjacent IgE molecules, inducing the mast cell to release histamine and other inflammatory chemicals from granules (vesicles) - These signals bring about the typical allergy symptoms: sneezing, runny nose, teary eyes, and smooth muscle contractions that result in breathing difficulty - Drugs called antihistamines diminish allergy symptoms (and inflammation) by blocking receptors for histamine - An acute allergic response sometimes leads to anaphylactic shock, a whole-body, life threatening reaction that can occur within seconds of exposure to an allergen - Anaphylactic shock develops when widespread release of mast cell contents triggers abrupt dilation of peripheral blood vessels, causing a precipitous drop in blood pressure, as well as constriction of blood flow and the inability to breathe
Citric Acid Cycle (general)
- Also called the tricarboxylic acid cycle or Krebs cycle - Functions as a metabolic furnace that oxidizes organic fuel derived from pyruvate - 2 molecules of CO2 per acetyl CoA - Cycle generates 1 ATP per turn by substrate-level phosphorylation, but most of the chemical energy is transferred by NAD+ and a related electron carrier, the coenzyme FAD (flavin adenine dinucleotide, derived from riboflavin), during the redox reactions - The reduced coenzymes, NADH and FADH2, shuttle their cargo of high-energy electrons into the electron transport chain - Regeneration of oxaloactetate (makes this process a cycle) - In eukaryotic cells, all the citric acid cycle enzymes are located in the mitochondrial matrix except for the enzyme that catalyzes step 6 (which resides in the inner mitochondrial membrane) - Carboxylic acids are represented in their ionized forms because the ionized forms prevail at the pH within the mitochondrion
Binding of a B Cell Antigen Receptor to an Antigen
- An early step in B cell activation - Eventually leads to formation of plasma cells that secrete a soluble form of the antigen receptor (antibody) - Bind to intact antigens in the blood and lymph
Distinction Between Anaerobic Respiration and Fermentation
- An electron transport chain is used in anaerobic respiration but not in fermentation
Reaction-Center Complex
- An organized association of proteins holding a special pair of chlorophyll a molecules - The pair of chlorophyll a molecules are special because their molecular environment enables them to use the energy from light to boost one of their electrons to a higher energy level and to transfer the electron to the primary electron acceptor
Calvin Cycle (general)
- Anabolic pathway, building carbohydrates from smaller molecules and consuming energy - Carbon enters the Calvin cycle in the form of CO2 and leaves in the form of sugar - Cycle spends ATP as an energy source and consumes NADPH as reducing power for adding high-energy electrons to make the sugar - Carbohydrate produced by the Calvin cycle is glyceraldehyde 3-phosphate - For the net synthesis of one molecule of G3P, the cycle must take place three times, fixing three molecules of CO2
Complex Interaction of the Helper T Cell
- Antigen receptors on the surface of the helper T cell surface binds to the antigen fragment and to the class II MHC molecule displaying that fragment on the antigen-presenting cell - An accessory protein on the helper T cell surface binds to the class II MHC molecule, helping keep the helper T cell and and antigen-presenting cell joined (as the two cells interact, signals in the form of cytokines are exchanged in both directions; extensive contact between the cell surfaces enables further information exchange) - Example: Cytokines secreted from a dendritic cell act in combination with the antigen to stimulate the helper T cell, causing it to produce its own set of cytokines - Antigen-presentation by a dendritic cell or macrophage activates a helper T cell which then proliferates, forming a clone of activated helper T cells - B cells (naive B cells) present antigens to ALREADY activated helper T cells, which in turn activate the B cells - Activated helper T cells also help stimulate cytotoxic T cells
Proton Motive Force
- Aqueous solutions inside and surround the cell are a ready source of H+ - Electron transfers cause H+ to be taken up and released in the surrounding solution - In eukaryotic cells, the electron carriers are spatially arranged in the inner mitochondrial membrane in such a way that H+ is accepted from the mitochondrial matrix and deposited in the intermembrane space - H+ gradient that results is called the proton-motive force, emphasizing the capacity of the gradient to perform work - The force drives H+ back across the membrane through H+ channels in ATP synthases - Prokaryotes use this force to make ATP, rotate flagella and to pump nutrients and waste products across the membrane
NAD+ (general)
- At key steps in cell respiration, electrons are stripped from the glucose - Generally, in oxidation reactions, each electron travels with a proton (a hydrogen atom) - The hydrogen atoms are not transferred directly to oxygen, but instead are usually passed first to an electron carrier (coenzyme called NAD+, nicotinamide adenine dinucleotide, a derivative of niacin) - Cycles easily between oxidized NAD+ and reduced NADH states - As an electron acceptor, NAD+ functions as an oxidizing agent during respiration - NAD+ is the most versatile electron acceptor in cellular respiration
Innate Defenses in Vertebrates Similar to Those found in Invertebrates
- Barrier defenses - Phagocytosis (Innate Cellular Degenses) - Antimicrobial Peptides
Electron Transport Chain (general)
- Consists of a number of molecules, mostly proteins, built into the inner membrane of the mitochondria of eukaryotic cells and the plasma membrane of aerobically respiring prokaryotes - Electrons removed from glucose are shuttled by NADH to the "top", higher energy end of the chain and at the "bottom", lower energy end, O2 captures these electrons along with hydrogen nuclei (H+), forming water - Electron transfer from NADH to oxygen is an exergonic reaction (ΔG = -53 kcal/mol, -222kJ/mol) - Electrons cascade down the cahin from one carrier molecule to the next in a series of redox reactions, losing a small amount of energy with each step until reaching oxygen, the terminal electron acceptor, which has a great affinity for electrons - Each downhill carrier is more electronegative than its uphill neighbor
Structure of T Cell Antigen Receptor / Just T Cell Receptor
- Consists of two different polypeptide chains: an α chain and a β chain linked by a disulfide bridge - Near the base of the T cell receptor is a transmembrane region that anchors the molecule in the cell's plasma membrane - At the outer tip of the molecule, the V regions of α and β chains together form a single antigen-binding site - Remainder of the molecule is made up of the C region - Bind only to fragments of antigens that are displayed (or presented) on the surface of host cells - Host protein that displays the antigen fragment on the cell surface is called an MHC (major histocompatibility complex) molecule (most body cells only have class I MHC molecules)
CAM Plants
- Crassulacean Acid Metabolism - Many succulent (water-storing) plants (i.e. cacti, pineapples, etc) - These plants open their stomata during the night and close them during the day (closing stomata during the day helps desert plants conserve water, but also prevents CO2 from entering the leaves) - During the night, these plants take up CO2 and incorporate it into a variety or organic acids - Mesophyll cells of CAM plants store the organic acids they make during the night in their vacuoules until morning - During the day, when the light reactions can supply ATP and NADPH for the Calvin cycle, CO2 is released from the organic acids - These two steps occur at separate times but within the same cell unlike C4 plants
Cytotoxic T Cells (Cell-Mediated Immune Response)
- Cytotoxic T cells are effector cells - Cytotoxic refers to their use of toxic gene products to kill infected cells - To become active, they require signaling molecules from helper T cells and interaction with an antigen-presenting cell - Fragments of foreign proteins produced in an infected host cells associated with class I MHC molecules are displayed on the cell surface for recognition by cytotoxic T cells - Cytotoxic T cells have an accessory protein that binds to the MHC molecule, helping keep the two cells in contact while the cell is activated - Once Activated, cytotoxic T cells can eliminate cells that are infected by viruses or other intracellular pathogens - Targeted destruction of an infected host cell by a cytotoxic T cell involves the secretion of proteins that disrupt membrane integrity and trigger apoptosis - Death of the infected cell deprives the pathogen of a place to reproduce and exposes cell contents to circulating antibodies which mark them for disposal
Antibody Function
- Doesn't actually kill pathogens, but by binding to antigens, they mark pathogens in various ways for inactivation or destruction - Simplest activity is neutralization: antibodies bind to viral proteins in order to prevent infection of a host cell (neutralizing the virus) - Similarly antibodies sometimes bind to toxins released in body fluids, preventing the toxins from entering body cells - Opsonization: antibodies bound to antigens on bacteria present a readily recognized structure for macrophages or neutrophils (When antibodies facilitate phagocytosis they also help fine-tune the humoral immune response (this positive feed back between innate and adaptive immunity contributes to a coordinated, effective response to infection) - Because each antibody has two antigen-binding sites, antibodies sometimes also facilitate phagocytosis by linking bacteral cells, virus particles, or other foreign substances into aggregates - Antibodies sometimes work together with the proteins of the complement system to dispose of pathogens - Binding of a complement protein to an antigen-antibody complex on a foreign cell (or an enveloped virus) triggers a cascade in which each protein of the complement system activates the next protein - Ultimately, activated complement proteins generate a membrane attack complex that forms a pore in the membrane of the foreign cells that cause it to swell and lyse - There is a mechanisms by which they can bring about death of infected body cells: when a virus uses a cell's biosynthetic machinery to produce viral proteins, these viral products can appear on the cell surface (if antibodies specific for epitopes on these viral proteins bind to the exposed proteins, the presence of the bound antibody at the cell surface can recruit a natural killer cell which releases proteins that cause the infected cell to undergo apoptosis)
Generation of B Cell Diversity
- Each person makes more than 1 million different B cell antigen receptors (only about 20,000 protein-coding genes in the human genome) - Capacity to generate diversity is built into the structure of Ig genes - A receptor light chain is encoded by three gene segments: a V segment, a joining (J) segment, and a C segment - The V and J segments together encode the V region of the receptor chain, while the C segment encodes the constant region - The light chain gene contains a single C segment, 40 different V segments, and 5 different J segments - These alternative copies of the V and J segments are arranged within the gene in a series - The pieces can be combined in 200 different ways - Early in B cell development, an enzyme complex called recombinase links one light-chain V gene segment to one J gene segment - This recombination event eliminates the long stretch of DNA between the segments, forming a single exon that is part V and part J - There is only an intron between the J and C DNA segments, no further DNA rearrangement is required - Instead, the J and C segments of the RNA transcript will be joined when splicing removes the intervening RNA - Recombinase acts randomly, linking any one of the 40 V gene segments to any one of the 5 J gene segments - Heavy chain genes undergo a similar rearrangement - In any given cell, only one allele of a light-chain gene and one allele of a heavy-chain gene are rearranged (the rearrangements are permanent and are passed on to the daughter cells when the lymphocyte divides) - After both the light and heavy chain genes have rearranged, antigen receptors can be synthesized - Each pair of randomly rearranged heavy and light chains results in a different antigen-binding site - For the total population of B cells in a human body, the number of such combinations is 3.5 x 10^6 - Mutations during VJ recombination add additional variation
Regulation
- Feedback inhibtion: Then end product of the anabolic pathway inhibts the enzyme that catalyzes an early step of the pathway (this prevents the needless diversion of key metabolic intermediates from uses that are more urgent) - Cell controls its catabolism, control is based mainly on regulating the activity of enzymes at strategic points in the catabolic pathway - Energy that keeps us alive is RELEASED not PRODUCED by cellular respriation
Closer Look at Electron Transport
- First molecule of the electron transport chain in complex I is transferred from NADH to flavoprotein (prosthetic group called flavin mononucleotide (FMN)) - Flavoprotein returns to oxidized state as it passes electrons to an iron-sulfur protein which then passes the electrons to a compound called ubiquinone (Q) (electron carrier that is a small hydrophobic molecule and is the only member of the electron transport chain that isn't a protein and is individually mobile within the membrane rather residing in a complex) - Most remaining electron carriers between ubiquinone and oxygen are proteins called cytochromes (prosthetic group, heme, has an iron atom that accepts and donates electrons) Last cytochrome of the chain, cyt a3, passes its electrons to oxygen - Each oxygen atom also picks up a pair of hydrogen ions to form water - FADH2 adds its 2 electrons to the chain from within complex II at a lower energy level - The electron transport chain provides about 1/3 less energy for ATP synthesis when the electron donor is FADH2 rather than NADH - Electron transport chain makes no ATP - Establishing the H+ gradient is a major function, the chain converts energy using the exergonic flow of electrons from NADH and FADH2 to pump H+ across the membrane (form the mitochondrial matrix into the intermembrane space) - H+ has a tendency to move back across the membrane, diffusing down its gradient and ATP synthase are the only sites that gives a route through the membrane for H+ - Certain members of the electron transport chain accept and release protons along with electrons
Five Forms of Immunoglobulin (Ig)
- For a given B cell, each form or class has an identical antigen-binding specificity, but a distinct heavy-chain C region - IgD: Only memrane bound form - IgM: The first class of soluble antibody produced - IgG: Second class of soluble antibody produced and is the most abundant antibody in blood - IgA - IgE
Tallying the Calvin Cycle
- For every 3 molecules of CO2 there are 6 molecules of G3P formed, but only one molecule of G3P can be counted as net gain of carbohydrate because the cycle began with 15 carbons' worth of carbohydrate in the form of three molecules of RuBP and it ends with 18 carbons' of carbohydrate
Energy Input and Output of Glycolysis
- Glycolysis can be divided into two phases: energy investment and energy payoff - During energy investment the cell actually spends ATP, but this investment is repaid with interest during the enegry payoff phase, when ATP is produced by substrate-level phosphorylation and NAD+ is reduced to NADH by electrons released from the oxidation of glucose - Net energy yield from glycolysis, per glucose molecule, is 2 ATP and 2 NADH (2H2O molecules are also formed) - All of the carbon originally present in glucose is accounted for in the two molecules of pyruvate
Chloroplast Structure
- Has an envelope of two membranes surrounding a dense fluid called the stroma - Suspended within the stroma is a third membrane system, made up of sacs called thylakoids, which segregates the stroma from the thylakoid space inside these sacs - Thylakoid sacs can be stacked in columns called grana - Chlorophyll, green pigment, resides in the thylakoid membranes of the chloroplasts
Innate Immunity: Inflammatory Response in Vertebrates (general)
- Histamine, an important inflammatory signaling molecule, is stored in the granules (vesicles) of mast cells, found in connective tissue - Histamine released at sites of damage triggers nearby blood vessels to dilate and become more permeable - Activated macrophages and neutrophils discharge cytokines, signaling molecules that enhance an immune response, in order to promote blood flow to the site of injury or infection - Increase in local blood supply causes the redness and increased skin temperature - Blood engorged capillaries leak fluid into neighboring tissues, causing swelling - Activated complement proteins promote further release of histamine, attracting more phagocytic cells that enter injured tisses and carry out additional phagocytosis (enhanced blood flow to the site helps deliver antimicrobial peptides--the result is an accumulation of pus, a fluid rich in white blood cells, dead pathogens, and cell debris from damaged tissue) - Sever tissue damage or infection may lead to a system response that causes injured or infected cells to secrete molecules that stimulate the release of addition neutrophils from the bone marrow - In a severe infection, such as meningitis or appendicitis, the number of white blood cells in the blood may increase several fold within a few horus - Fever: Substances released by activated macrophages cause the body's thermostat to reset to a higher temperature (elevated body temperature may enhance phagocytosis and speed up chemical reactions) - Septic shock: Overwhelming systemic inflammatory response characterized by high fever, low blood pressure, and poor blood flow through capillaries (usually occurs in the very old or very young)
Carotenoids
- Hydrocarbons that are various shades of yellow and orange because they absorb violet and blue-green light - May broaden the spectrum of colors that can drive photosynthesis - Important function is photoprotection: When carotenoids absorb and dissipate excessive light energy that would otherwise damage chlorophyll or interact with oxygen, forming reactive oxidative molecules that are dangerous to the cell - Carotenoids in the human eye have a photoprotective role too
Secondary Immune Response
- If an individual is exposed again to the same antigen, the response is faster (typically peaking only 2 - 7 days after exposure), of greater magnitude, and more prolonged - This is a hallmark of adaptive/acquired immunity - Memory cells of the helper T cell, cytotoxic T cell and B cells enable the secondary response
Oxidation of Pyruvate to Acetyl CoA / Oxidative Decarboxylation / Link Reaction
- If molecular oxygen is present after glycolysis, the pyruvate (a charged molecule) enters a mitochondrion via active transport with the help of a transport protein - Pyruvate is first converted to a compound called acetyl coenzyme A--this step, linking glycolysis and the citric acid cycle, is carried out by a mutlienzyme complex (pyruvate dehydrogenase complex) that catalyzes three reactions 1) Pyruvates carboxyl group, which is already fully oxidized (has little chemical energy) is removed and given off as a molecule of CO2 and will diffuse out of the cell 2) The remaining two-carbon fragment is oxidized forming acetate. The extracted electrons are transferred to NAD+, storing energy in the form of NADH 3) Finally coenzyme A, a sulfur-containing compound derived from a B vitamin, is attached via its sulfur atom to the acetate, forming acetyl Co A (which has high potential energy)
Innate Immunity Fruit Fly Example 2
- If the fly is instead infected by the bacterium Micrococcus luteus, a different recognition protein is activated and the fly produces a different set of antimicrobial peptides effective against M. luteus and many related bacteria
Four Major Characteristics of Adaptive Immunity
- Immense diversity of lymphocytes and receptors, enabling the immune system to detect pathogens never before encountered - Adaptive immunity normally has self-tolerance, the lack of reactivity against an animal's own molecules and cells - Cell proliferation triggered by activation greatly increases the number of B and T cells specific for an antigen - There is a stronger and more rapid response to an antigen encountered previously, due to a feature known as immunological memory
Innate Immunity: Barrier Defenses in Vertebrates
- In mammals, epithelial tissues block the entry of many pathogens - Barrier defenses include: Skin and mucous membranes lining the digestive, respiratory, urinary and reproductive tracts - Certain cells of the mucous membranes produce mucus (a viscous fluid that enhances defenses by trapping microbes and particles) - Ciliated epithelial cells sweep mucus and any entrapped microbes upward and out of the trachea to help prevent infection in the lungs - Saliva, tears, and mucous secretions that bathe various exposed epithelia also provide a washing action that inhibits colonization by fungi and bacteria - Lysozyme in tears, saliva, and mucous secretions destroys the cells walls of susceptible bacteria as they enter the openings around the eyes or the upper respiratory tract - Microbes in food or water and those in swallowed mucus must also contend with the acidic environment of the stomach (which kills most of them before entering intestines) - Secretions from oil and sweat glands give human skin a pH ranging from 3 to 5, acidic enough to prevent the growth of many bacteria
Innate Immunity: Antimicrobial Peptides and Proteins in Vertebrates (general)
- In mammals, pathogen recognition triggers the production and release of a variety of peptides and proteins that attack pathogens or impede their reproduction - Some function like the antimicrobial peptides of insects, damaging broad groups of pathogens by disrupting membrane integrity - Others such as interferons and complement proteins are unique to vertebrate immune systems
Chemiosmosis in Chloroplasts vs. Mitochondria
- In mitochondria, the high-energy electrons dropped down the transport chain are extracted from organic molecules (which are oxidized) - In chloroplasts, the source of electrons is water - Chloroplasts do not need molecules from food to make ATP; their photosystems capture light energy and use it to drive the electrons from water to the top of the transport chain - Inner membrane of the mitochondrion pumps protons from the mitochondrial matrix out to the intermembrane space (which serves as a reservoir of H+) - The thylakoid membrane of the chloroplast pumps protons from the stroma into the thylakoid space (interior of the thylakoid) which functions as the H+ reservoir - In the mitochondrion, protons diffuse down their concentration gradient from the intermembrane space through ATP synthase to the matrix, driving ATP synthesis - In the chloroplast, ATP is synthesized as the hydrogen ions diffuse from the thylakoid space back to the stroma through ATP synthase complexes, whose catalytic knobs are on the stroma side of the membrane (ATP and NADPH form in the stroma) - H+ gradient or pH gradient across the thylakoid membrane is substantial ( pH in thylakoid space drops to about 5 (H+ increases) and the pH in the stroma increases to about 8. Three pH untis corresponds to a thousandfold difference in H+ concentration
Autoimmune Diseases
- In some people, the immune system is active against particular molecules of the body, causing an autoimmune disease - In systematic lupus erythematosus, the immune system generates antibodies against histones and DNA released by the normal breakdown of body cells - These self-reactive antibodies cause skin rashes, fever, arthritis, and kidney dysfunction - Rheumatoid arthritis leads to damage and painful inflammation of the cartilage and bone of joints - In type 1 diabetes mellitus, the insulin-producing beta cells of the pancreas are the targets of autoimmune cytotoxic T cells -The most common chronic neurological disorder in developed countries is multiple sclerosis: T cells infiltrate the central nervous system and the result is the destruction of the myelin sheath that surrounds parts of many neurons (leading to muscle paralysis through a disruption in neuron function) - Gender, genetics, and environment all influence susceptibility to autoimmune disorders
Two Stages of Photosynthesis (general)
- Light reactions: Solar energy is captured and transformed into chemical energy - Calvin Cyle: Chemical energy is used to make organic molecules of food
Dendritic Cells
- Mainly populate tissues (such as skin) that have contact with the environment - Stimulate adaptive immunity against pathogens they encounter and engulf - Reside outside of the lymphatic system, but they migrate to lymph nodes after interaction with pathogens (and within the lymph nodes, dendritic cells interact with other immune cells to stimulate adaptive immunity)
Calvin Cycle (basic)
- Makes sugar through this process - Begins by incorporating CO2 from the air into organic molecules already present in the chloroplast - Carbon fixation: The initial incorporation of carbon into organic compounds - Reduces the fixed carbon to carbohydrate by the addition of electrons from NADPH and through the use of chemical energy in the form of ATP - Can also be referred to as the light-independent reactions - Occurs in the stroma
Catabolic Pathway
- Metabolic pathways that released stored energy by breaking down complex molecules - Electron transfer plays a major role in these pathways - Linked to work by a chemical drive shaft (ATP) - To keep working, the cell must regenerate its supply of ATP
Vaccination Dilemmas
- Misinformation about vaccine safety and disease risk has led some patients to refuse to immunize their children with available and effective vaccines
Exertion, Stress, and the Immune System
- Moderate exercise improves immune system function and significantly reduces the risk of these infections - Too much exercise to the point of exhaustion leads to more frequent infections and to more severe symptoms - Psychological stress has been shown to disrupt immune system regulation by altering the interplay of the hormonal, nervous, and immune systems - Adults who averaged few than 7 hours of sleep a night got sick three times as often when exposed to a cold virus as individuals who averaged at least 8 hours of sleep
Guanosine Triphosphate
- Molecule similar to ATP in its structure and cellular function - GTP may be used to make an ATP molecule or directly power work in the cell - In the cells of plants, bacteria, and some animal tissues, step 5 forms an ATP molecule directly by substrate-level phosphorylation - This output represents the only ATP generated during the citric acid cycle
Versatility of Catabolism
- Most calories are obtained in the form of fats, proteins, sucrose, and starch - Proteins can also be used for fuel, but first they must be digest to their constiuent amino acids - Amino acids present in excess are converted by enzymes to intermediates of glycolysis and the citric acid cycle - Before amino acids can feed into glycolysis or the citric acid cycle, their amino groups must be removed through deamination - A metabolic sequence called beta oxidation breaks the fatty acids down to two carbon fragments, which enter the citric acid cycle as acetyl CoA; NADH and FADH2 are also generated during this process and can enter the electron transport chain - A gram of fat oxidized by respiration produces more than twice as much ATP as a gram of carbohydrate
C4 Plants
- Named C4 because they preface the Calvin cycle with an alternate mode of carbon-fixation that forms a four-carbon compound as its first product - Several thousands of plant species (at least 19 families) use this method such as sugarcane, corn, and some grasses - C4 plants have two distinct types of photosynthetic cells: bundle-sheath cells and mesophyll cells - Bundle-sheath cells are arranged into tightly packed sheaths around the veins of the leaf - Between the bundle sheath and the leaf surface are the more loosely arranged mesophyll cells - Calvin cycle is confined to the chloroplasts of the bundle sheath cells, but the Calvin cycle is preceded by incorporation of CO2 into organic compounds in the mesophyll cells - C4 photosynthesis minimizes photorespiration and enhances sugar production (this adaptation is advantageous in hot regions)
Heterotroph
- Obtain their organic material by the second major mode of nutrition - Live on compounds produced by other organisms - Biosphere consumers - Feed on plants, animals, dead organisms (by decomposing and feeding on organic litter such as carcasses, feces, and fallen leaves, i.e. these are called decomposers, most fungi and prokaryotes get nourishment this way)
Glycolysis (general)
- Occurs in the cytosol - Glycolysis means "sugar splitting" - Glucose is a six-carbon sugar that gets split into two three-carbon sugars - These triose sugars are then oxidized and their remaining atoms rearranged to form two molecules of pyruvate - Pyruvate is the ionized form of pyruvic acid - Releases less than a quarter of the chemical energy in glucose that can be released in cells; most of the energy remains stockpiled in the two molecules of pyruvate
Facultative Anaerobes
- Oragnisms including yeast and bacteria can make enough ATP to survive using fermentation or respiration - Human muscle cells behave as facultative anaerobes - Pyruvate is a fork in the metabolic road that leads to two alternative pathways - When fermenting a facultative anaerobe has to consume sugar at a much faster rate
Obligate Anaerobes
- Organisms that carry out only fermentation or anaerobic respiration - Can not survive in the presence of oxygen - A few cell types, such as cells of the vertebrate brain, can carry out only aerobic oxidation of pyruvate
Chlorophyll a
- Participates directly in in the light reactions - Spectrum suggests that violet-blue and red light work best for photosynthesis, since they are absorbed, while green is least effective - Blue-green
Antigenic Variation
- Pathogens can escape the body's defenses by altering how it appears to the immune system - If a pathogen that expressed previously encountered epitopes, but no longer does so, it can reinfect or remain in a host without triggering the rapid and robust response that memory cells probvide - Changes in epitope expression (antigenic variation) are regular events for some viruses and parasites - This is the main reason why the influenza virus remains a major public health problem - As it replicates in one human host after another, the human influenza virus mutates - Any change that lessens recognition by the immune system provides a selective advantage, the virus steadily accumulates such alterations - Changes in the surface proteins of the influenza virus are the reason that a new flu vaccine must be manufactured and distributed each year
Innate Immunity: Cellular Defenses in Vertebrates (general)
- Phagocytic cells detect fungal or bacterial components using several types of receptors - Many cellular innate defenses involve the lymphatic system (a network that distributes the fluid called lymph throughout the body) - Mammalian Toll-like receptors (TLR) bind to fragments of molecules characteristic of a set of pathogens (the recognized macromolecule is normally absent from the vertebrate body) - After detection of pathogens, a phagocytic cell engulfs them by trapping them in a vacuole - The vacuole fuses with a lysosome leading to destruction of the invaders in two ways: Gases produced in the lysosome poison the engulfed pathogens and lysozyme (and other enzymes) in the lysosome degrade the components of the pathogens
Cyclic Electron Flow
- Photoexcited electrons can take an alternative path which uses photosystem I but not photosystem II - Short circuit: The electrons cycle back from Fd to the cytochrome complex and from there continue on to a P700 chlorophyll in the PS I reaction-center complex - No production of NADPH and no release of oxygen, but ATP is generated - Several groups of photosynthetic bacteria don't have a photosystem II (i.e. purple sulfur bacteria) so cyclic electron flow is the sole means of generating ATP in photosynthesis - Can also occur in photosynthetic species that possess both photosystems (includes some prokaryotes (cyanobacteria) as well as certain eukaryotic photosynthetic species as an evolutionary left over)
Photosynthesis as a Redox Process
- Photosynthesis reverses the direction of electron flow (vs. cell respiration in the electron transport chain) - Water is split and electrons are transferred along with hydrogen ions from the water to CO2, reducing it to sugar - Electrons increase in potential energy as they move from water to sugar so energy is required for this endergonic process and the energy boost is from light
Two Types of Photosystems that Populate the Thylakoid Membrane
- Photosystem II (PS II, functions first in the light reactions) - Photosystem I (PS I)
C3 Plants
- Plants in which the initial carbon fixation occurs via rubisco - First organic product of carbon fixation is a three-carbon compound (3-phosphoglycerate) - Rice, wheat, and soy beans
Monoclonal Antibodies
- Prepared from a single clone of B cells grown in culture - Identical and specific for the same epitope on an antigen for the same epitope on an antigen - Provided the basis for many recent advances in medical diagnosis and treatment - Example: Home pregnancy kits use monoclonal antibodies to detect human chorionic gonadotropin (hCG)--because hCG is produced as soon as an embryo implants in the uterus the presence of this hormone in a woman's urine is a reliable indicator for a very early stage of pregnancy
Interferons
- Proteins that provide innate defense by interfering with viral infections - Limit the cell-to-cell spread of viruses in the body, helping to control viral infections - Virus infected body cells secrete interferons which case nearby uninfected cells to produce substances that inhibit viral reproduction - Some white blood cells secrete a different type of interferon that helps activate macrophages (and enhances their phagocytic ability)
Lactic Acid Fermentation
- Pyruvate is reduced directly by NADH to form lactate as an end product, with no release of CO2 - Used by certain fungi and bacteria - Human muscle cells make ATP by lactic acid fermentation when oxygen is scarce
Redox Reactions
- Relocation of electrons releases energy stored in organic molecules, and this energy is ultimately used to synthesize ATP - The loss of electrons from one substance to another substance is called oxidation - The addition of electrons to another substance is known as reduction - Electron donor is called the reducing agent - Electron acceptor is called the oxidizing agent - The more electronegative an atom (the stronger its pull on electrons), the more energy is require to take an electron away - An electron loses potential energy when it shifts from a less electronegative atom toward a more electronegative atom - A redox reaction that moves electrons closer to oxygen releases chemical energy that can be put to work
Innate Immunity (invertebrates/insects)
- Repels and fights infection with only this type of immunity - Insects rely on their exoskeleton as a first line of defense against infection (composed largely of the polysaccharide chitin) - A chitin-based barrier is also present in the insect intestine, where it blocks infection by many pathogens ingested with food - Lysozyme (an enzyme that breaks down bacterial cell walls) further protects the insect digestive system - Immune cells called hemocytes travel throughout the body in the hemolymph - Some hemocytes carry out phagocytosis (the cellular ingestion and digestion of bacteria and other foreign substances) - Other hemocytes trigger the production of chemicals that kill pathogens and help entrap large parasites - Encounters with pathogens in the hemolymph cause hemocytes (and other cells) to secrete antimicrobial peptides (short chains of amino acids) that circulate throughout the body and inactivate or kill fungi and bacteria by disrupting their plasma membranes - Immune cells of insects secrete specialized recognition proteins that bind to molecules found only in the outer layers of fungi or bacteria - Fungal cell walls contain unique polysaccharides, whereas bacterial cell walls have polymers composed of combinations of sugars and amino acids not found in animal cells--these macromolecules serve as identity tags in pathogen recognition
Immunological Memory (general)
- Responsible for the long-term protection that a prior infection or vaccination provides against many diseases (such as chickenpox) - Prior exposure to an antigen alters the speed, strength, and duration of the immune response - Because selected B cells give rise to plasma cells, measuring the concentrations of specific antibodies in blood over time distinguishes the primary and secondary immune responses - Secondary immune response relies on the reservoir of T and B memory cells generated following initial exposure to an antigen (memory cells are long lived, they provide the basis for immunological memory, which can span many decades) - Memory cells specific for that antigen enable the rapid formation of clones of thousands of effector cells also specific for that antigen, thus generating a greatly enhanced immune defense
Visible Light
- Segment most important to life is the narrow band from about 380nm to 750nm in wavelength - Can be detected as various colors by the human eye - The radiation that drives photosynthesis
Epitope / Antigenic Determinant (general)
- Small accessible portion of an antigen that binds to an antigen receptor (i.e. a group of amino acids in a particular protein) - All antigen receptors produced by a single B cell or T cell are identical - A single antigen usually has several different epitopes, each binding a receptor with a different specificity - Each B cell or T cell displays specificity for a particular epitope, enabling it to respond to any pathogen that produces molecules containing that same epitope
Substrate-Level Phosphorylation
- Smaller amount of ATP is formed directly in a few reactions of glycolysis and the citric acid cycle - This mode of ATP synthesis occurs when an enzyme transfers a phosphate group from a substrate molecule to ADP
Antibody (or Immunoglobulin, Ig)
- Soluble-protein form of the antigen receptor secreted by plasma cells - Have the same Y-shaped organization as B cell antigen receptors, but they are not membrane bound - Antibodies (rather than the B cells) actually help defend against pathogens - Antigen-binding site has a unique shape that provides a lock-and-key fit for a particular epitope - Bind to intact antigens in the blood and lymph (can bind to antigens on the surface of pathogens or free in body fluids)
Antigen Receptor (general)
- Specific enough to bind to just one part of one molecule from a particular pathogen (such as a species of bacteria or a strain of virus - Although the cells of the immune system produce millions of different antigen receptors, all of the antigen receptors made by a single B or T cell are identical - There are about 100,000 antigen receptors on the surface of a single B or T cell
Autotroph
- Sustain themselves without eating anything derived from other living beings - Produce their organic molecules from CO2 and other inorganic raw materials obtained from the environment - Ultimate sources of organic compounds for all nonautotrophic organisms - Producers of the biosphere - Almost all plants: Only nutrients they require are water and minerals from the soil and CO2 from the air
TLR Examples
- TLR3: Present on the inner surface of vesicles formed by endocytosis, is the sensor for double-stranded RNA, a form of nucleic acid characteristic of certain viruses - TLR4: Located on immune cell plasma membranes, recognizes lipopolysaccaride, a type of molecule found on the surface of many bacteria - TLR5: Recognizes flagellin, the main protein of bacterial flagella
Activation/Proliferation of a Lymphocyte (general)
- The binding of an antigen receptor to an epitope initiates events that activate the lymphocyte - Undergoes multiple cell divisions - Result of this proliferation is a clone (a population of cells that are identical to the original cell) - Some cells from this clone become effector cells (short lived cells that take effect immediately against the antigen and any pathogens producing that antigen) - Remaining cells in the clone become memory cells (long lived cells that can give rise to effector cells if the same antigen is encountered later in the animal's life) - Process is called clonal selection because an encounter with an antigen selects which lymphocytes will divide to produce a clonal population of thousands of cells specific for a particular epitope
Active Immunity
- The defenses that arise when a pathogen infects the body and prompts a primary or secondary immune response - Can develop from the introduction of antigens into the body through immunization (vaccination) - Today many sources of antigen are used to make vaccines such as inactivated bacterial toxins, killed pathogens, parts of pathogens, weakened pathogens that generally do not cause illness, and even genes encoding microbial proteins - Later in life, IgA functions in active immunity because it is secreted in tears, saliva, and mucus in order to protect mucous membranes of both males and females
Phosphofructokinase
- The enzyme that catalyzes step 3 of glycolysis - First step that commits the substrate irreversible to the glycolytic pathway - By controlling this step, the cell can speed up or slow down the entire catabolic process - the pacemaker of cell respiration - Allosteric enzyme with receptor for specific inhibitors and activators - It is inhibited by ATP and stimulated by adenosine monophosphate (AMP) which the cell derives from ADP - As ATP accumulates, inhibition of the enzyme slows down glycolysis - The enzyme becomes active again as cellular work converts ATP to ADP faster than ATP is being regenerated - Also sensitive to Citrate
Attack on the Immune System: HIV
- The human immunodeficiency virus (HIV), the pathogen that causes the acquired immunodeficiency syndrome (AIDS), both escapes and attacks the adaptive immune response - When introduced to the body, HIV infects helper T cells with high efficiency by binding specifically to the CD4 accessory protein - HIV also infects some cell types that have low levels of CD4 (such as macrophages and brain cells) - In the cell, the HIV RNA genome is reverse transcribed and the product DNA is integrated into the host cell's genome (the viral genome can direct production of new virus particles) - HIV persists because of antigenic variation--the virus mutates at a very high rate during replication, altered proteins on the surface of some mutated viruses reduce interaction with antibodies and cytotoxic T cells (such viruses survive, proliferate, and mutate more) - Viral reproduction and cell death triggered by the virus lead to loss of helper T cells which impairs both humoral and cell-mediated immune responses - Opportunistic diseases, nerve damage, and body wasting are the primary causes of death in AIDS patients - Transfer of HIV requires the transfer of virus particles or infected cells from person to person via body fluids such as semen, blood, breast milk, or through the use of contaminated needles
Alternative Mechanisms of Carbon Fixation
- There can be a compromise between the photosynthesis and the prevention of excessive water loss from the plant - CO2 required for photosynthesis enters a leaf via stomata (pores of the leaf surface) - Stomata are also the main avenues of transpiration (the evaporative loss of water from leaves) - On hot, dry days most plants close or partially close their stomata which conserves water, but also reduces photosynthetic yield by limiting access to CO2
Natural Killer Cells
- Unique aspect of vertebrate innate immunity - Type of lymphocyte that remains in the blood - Circulate through the body - Detect the abnormal array of surface proteins characteristic of some virus-infected and cancerous cells - Don't engulf stricken cells, but release chemicals that lead to cell death
Light Reactions (basic)
- Water is split, providing a source of electrons and protons and giving off O2 as a by-product - Light absorbed by chlorophyll drives a transfer of the electrons and hydrogen ions from water to an acceptor called NADP+ (nicotinamide adenine dinucleotide phosphate) where they are temporarily stored - NADP+ differs from NAD+ only by the presence of an extra phosphate group - Light reactions use solar power to reduce NADP+ to NADPH by adding 2 electrons and a proton - Light reactions generate ATP, using chemiosmosis to power the addition of a phosphate group to ADP (photophosphorylation) - Thylakoids of the chloroplasts are the sites of the light reactions
Excitation of Chlorophyll by Light
- When a molecule absorbs a photon of light, one of the molecule's electrons is elevated to an orbital where it has more potential energy - When the electron is in its normal orbital, the pigment molecule is said to be in its ground state - Absorption of a photon boosts an electron to an orbital of higher energy, and the pigment molecule is then said to be excited - Only photons absorbed are those whose energy is exactly equal to the energy difference between the ground state and an excited state - Once absorption of a photon raises an electron from the ground state to an excited state, the electron cannot remain there long (excited state is unstable) - Generally, when isolated pigment molecules absorb light, their excited electrons drop back down to the ground state orbital in a billionth of a second, releasing their excess energy as heat (some also emit light) - As excited electrons fall back to ground state, photons are given off and this afterglow is called fluorescence (chlorophyll will fluoresce red-orange
Photorespiration
- When a plants stomata partially close on hot dry days certain plants (C3) produce less sugar because the declining level of CO2 in the leaf starves the Calvin cycle - Rubisco can also bind in O2 in place of CO2 and as CO2 becomes scarce within the air spaces of the leaf, rubisco adds O2 to the Calving cycle instead of CO2 - Product splits and a two-carbon compound leaves the chloroplast (peroxisomes and mitochondria rearrange and split this compound, releasing CO2) - Occurs in the light and consumes O2 while producing CO2 - Generates no ATP (actually consumes ATP) - Produces no sugar (decreases photosynthetic output by siphoning organic material from the Calvin cycle and releasing CO2 that would otherwise be fixed - Probably evolutionary baggage from when the atmosphere had less O2 and more CO2 - Can play a protective role in plants because plants that can't carry out photorespiration are more susceptible to damage induced by excess light (photorespiration neutralizes the damaging products of the light reactions, which build up when a low CO2 concentration limits the progress of the Calvin cycle - Drains away as much as 50% of the carbon fixed by the Calvin cycle
Innate Immunity Fruit Fly Example 1
- When the fungus Neurospora crassa infects a fruit fly, pieces of the fungal cell wall bind a recognition protein--the complex activates the protein Toll (a receptor on the surface of hemocytes) - Signal transduction from the Toll receptor to the cell nucleus leads to synthesis of a set of antimicrobial peptides active against fungi
Structure of B Cell Antigen Receptor
- Y-shaped molecule consisting of four polypeptide chains: two identical heavy chains and two identical light chains, with disulfide bridges linking the chains together - A transmembrane region near one end of each heavy chain anchors the receptor in the B cell's plasma membrane (short tail region at the end of the heavy chain extends into the cytoplasm) - Light and heavy chains each have a constant (C) region where amino acid sequences vary little among the receptors on different B cells (C region includes the cytoplasmic tail and transmembrane region of the heavy chain and all of the disulfide bridges) - Within the two tips of the Y shape, the light and heavy chains each have a variable (V) region (because its amino acid sequence varies extensively from one B cell to another) - Together, parts of a heavy-chain V region and a light chain V region form an asymmetrical binding site for an antigen - Each B cell antigen receptor has two identical antigen-binding sites - Antigen-binding site has a unique shape that provides a lock-and-key fit for a particular epitope - Differences in the amino acid sequences of V regions provide the variation in binding surfaces that enables this highly specific binding
Identify the correct statement(s) about the resting membrane potential of a cell. Select all that apply.
-Potassium (K+) and sodium (Na+) gradients are maintained by active transport in a resting mammalian neuron. -Concentration gradients of potassium (K+) and sodium (Na+) across the plasma membrane represent potential energy.
Blood pressure is the force behind the filtration of substances out of the glomerulus and into Bowman's capsule.
...
The kidneys remove nitrogenous wastes from the blood and eliminate them in the urine.
...
The osmoregulatory problems of freshwater animals are opposite to those of marine animals. Freshwater fish are adapted to life in a hypotonic environment and have mechanisms to get rid of excess water absorbed into the body. Saltwater fish are adapted to the marine environment and have extracellular fluids that have a composition similar to seawater. Placing them in fresh water will upset their osmotic balance, and they may not have regulatory mechanisms that can compensate.
...
How Linear Electron Flow During the Light Reactions Generates ATP and NADPH
1) A photon of light strikes a pigment molecule in a light harvesting complex of PS II, boosting one of its electrons to a higher energy level. As this electron falls back to its groundstate, an electron in a nearby pigment molecule is simultaneously raised to an excited state. The process continues, with the energy being relayed to other pigment molecules until it reaches the P680 pair of chlorophyll a molecules in the PS II reaction-center complex. It excites an electron in this pair of chlorophylls to a higher energy state 2) This electron is transferred from the excited P680 to the primary electron acceptor. We can refer to the resulting form of P680, missing an electron, as P680+ 3) An enzyme catalyzes the splitting of a water molecule into two electrons, two hydrogen ions, and an oxygen atom. The electrons are supplied one by one to the P680+ pair, each electron replacing one transferred to the primary electron acceptor. (P680+ is the strongest biological oxidizing agent known; its electron "hole" must be filled. This greatly facilitates the transfer of electrons from the split water molecule) The H+ are released into the thylakoid lumen. The oxygen atom generated by the splitting of another water molecule, forming O2 4) Each photoexcited electron passes from the primary electron acceptor of PS II or PS I via an electron transport chain. The electron transport chain between PS II and PS I is made up of the electron carrier plstoquinone (Pq), a cytochrome complex, and a protein called plastocyanin (Pc) 5) The exergonic "fall" of electrons to a lower energy level provides energy for the synthesis of ATP. As electrons pass through the cytochrome complex, H+ are pumped into the thylakoid lumen, contributing to the proton gradient that is subsequently used in chemiosmosis 6) Meanwhile, light energy has been transferred via light-harvesting complex pigments to the PS I reaction-center complex, exciting an electron of the P700 pair of chlorophyll a molecules located there. The photoexcited electron was then transferred to PS I's primary electron acceptor, creating an electron "hole" in the P700 called P700+. P700+ can now act as an electron acceptor, accepting an electron that reaches the bottom of the electron transport chain from PS II 7) Photoexcited electrons are passed in a series of redox reactions from the primary electron transport chain of PS I down a second electron transport chain through the protein ferredoxin (Fd) (this chain does not create a proton gradient and thus does not produce ATP) 8)The enzyme NADP+ reductase catalyzes the transfer of electrons from Fd to NADP+. Two electrons are required for its reduction to NADPH. This molecule is at a higher energy level than water, and its electrons are more readily available for the reactions of the Calvin cycle than were those of water. This process also removes an H+ from the stroma
Central Role of Helper T Cells In Humoral and Cell Mediated Immune Responses
1) After an antigen-presenting cell engulfs and degrades a pathogen, it displays antigen fragments complexed with class II MHC molecules on the cell surface. A specific helper T cell binds to a displayed complex via its antigen receptor an an accessory protein (CD4). This interaction promotes secretion of cytokines by the antigen-presenting cell 2) Proliferation of the helper T cell stimulated by cytokines from both the antigen-presenting cell and the helper T cell gives rise to a clone of activated helper T cells, all with receptors for the same MHC-antigen fragment complex
Killing Action of Cytotoxic T Cells on an Infected Host Cell
1) An activated cytotoxic T cell binds to a class I MHC-antigen fragment complex on an infected cell via its antigen receptor and an accessory protein (CD8) 2) The T cell releases perforin molecules, which form pores in the infected cell membrane, and granzymes (enzymes that break down proteins) that enter the infected cell by endocytosis 3) Granzymes initiate apoptosis within the infected cell, leading to fragmentation of the nucleus and cytoplasm and eventual cell death
Major Events in a Local Inflammatory Response (Diagram)
1) At the injury site, mast cells release histamines, and macrophages secrete cytokines. These signaling molecules cause nearby capillaries to dilate 2) Capillaries widen and become more permeable , allowing fluid containing antimicrobial peptides to enter the tissue. Signals released by immune cells attract neutrophils 3) Neutrophils digest pathogens and cell debris at the site, and the tissue heals
Calvin Cycle (in depth)
1) Incorporates each CO2 molecule, one at a time, by attaching it to a five-carbon sugar named ribulose bishphosphate (RuBP). Enzyme that catalyzes this step is RuBP carboxylase, or rubisco (most abundant protein in chloroplasts and is also thought to be the most abundant protein on earth). Two molecules of 3-phosphoglycerate are formed per each fixed CO2 2) Each molecule of 3-phosphoglycerate receives an additional phosphate group from ATP, becoming 1,3-bisphosphoglycerate. A pair of electrons donated from NADPH reduces a carboxyl group on 1,3-bisphosphoglycerate to the aldehyde group of G3P, which stores more potential energy. 3) Carbon skeletons of five molecules of G3P are rearranged by the last steps of the Calvin cycle into three molecules of RuBP (to do this, the cycle spends 3 more ATP)
Light Reactions and Chemiosmosis: Organization of the Thylakoid Membrane
1) Water is split by photosystem II on the side of the membrane facing the thylakoid space 2) As Pq, a mobile carrier, transfers electrons to the cytochrome complex, four protons are translocated across the membrane into the thylakoid space 3) A hydrogen ion is removed from the stroma when it is taken up by NADP+. Diffusion of H+ from the thylakoid space back to the stroma (along the H+ concentration gradient) powers the ATP chemical energy in NADPH and ATP, which shuttle the energy to the Calvin cycle
c Level: 2
53. The sensation of thirst results from A) an increase in the plasma volume. B) hypertension (increased blood pressure). C) stimulation of osmoreceptor cells in the hypothalamus. D) a decrease in the osmolality of the extracellular fluid. E) stimulation of baroreceptors.
b Level: 1
55. Under normal conditions, most water loss from the body is through the A) skin. B) kidneys. C) lungs. D) GI tract. E) sweat.
d Level: 2
56. Which of the following is an example of water conservation by the body? A) diarrhea B) perspiration C) decreased water intake D) decreased urine volume E) increased urine volume
c Level: 1
57. Sensible perspiration A) contains only water. B) is water lost through simple evaporation. C) is secreted by the sweat glands. D) is invisible on the skin. E) is secreted by salivary glands.
effects of Aldosterone?
1. Na retention in collecting tubule--leads to water rent ion and increase in blood volume 2. regulation of extracellular volume 3. K elimination/potassium homeostasis 4. excretion of H+
Juxtaglomerular apparatus is controlled by what 2 main stimuli
1. pressure 2. activation of renal sympathetic nerve 3. decrease in tubular Na
ADH synthesis and secretion steps
1. produced as a preprohormone in hypothalamus 2. cleaved to prohormone and packaged in golgi (along with convertases) 3. intra-axonal transport to axon terminal and cleaved to ADH + inactive nuerophysin II 4. stored in herring bodies at axon terminal 5. stimulus at magnocellular cells causes AP and fusion of vesicles to release ADH to circulation
what are non regulated methods of water excretion (3)
1. sweating from skin 2. respiration from lungs 3. defecation from GI
How does the kidney keep cortisol from binding to mineral corticoid receptor?
11BHSD2 enzyme in kidney converts cortisol to an inactive compound (cortisone) so that it cannot bind
b Level: 2
15. When aldosterone is absent, sodium reabsorption in the nephron is A) greatly increased. B) greatly decreased. C) unchanged.
How many different combinations of maternal and paternal chromosomes can be packaged in gametes made by an organism with a diploid number of 8 (2n = 8)?
16
c Level: 2
19. Which of the following events occurs last? A) release of renin by the kidney B) release of aldosterone by the adrenal cortex C) sodium reabsorption by the kidney tubules D) angiotensinogen angiotensin I E) angiotensin I angiotensin II
c Level: 2
22. Antidiuretic hormone (ADH) A) increases plasma osmolality. B) is secreted by the anterior pituitary. C) increases water reabsorption in the kidneys. D) causes the production of a large volume of urine. E) increases urine volume.
d Level: 3
23. A decrease in plasma osmolality would increase A) ADH production. B) plasma sodium levels. C) renin production. D) urine production. E) thirst.
c Level: 1
24. The stimulus for secretion of atrial natriuretic hormone is increased A) blood osmolality. B) aldosterone production. C) blood pressure in atria of heart. D) blood pressure in kidney's afferent arterioles. E) blood pressure in the ventricles of the heart.
e Level: 2
25. Elevated blood pressure under resting conditions results in increased urinary output because A) baroreceptors signal the hypothalamus to increase ADH secretion. B) elevated blood pressure stimulates renin secretion. C) the amount of angiotensin II formed is increased. D) aldosterone levels increase. E) baroreceptors signal the hypothalamus to decrease ADH secretion.
d Level: 3
26. You've been working outside in the hot sun and are dripping wet with sweat. Your fluid intake has been minimal as you have been too busy to stop and get a drink. You would expect A) your blood osmolality to be low. B) an increase in the production of urine. C) aldosterone levels to decrease. D) ADH levels to increase. E) ADH levels to decrease.
b Level: 2
27. Increased ADH secretion could be stimulated by which of the following situations? A) increased renal blood flow B) increased blood osmolality C) increased atrial natriuretic hormone production D) increased blood pressure E) decreased blood osmolality
If the DNA content of a diploid cell in the G1 phase of the cell cycle is x, then the DNA content of the same cell at metaphase of meiosis I would be
2X
The following steps refer to various stages in transmission at a chemical synapse. 1. Neurotransmitter binds with receptors associated with the postsynaptic membrane. 2. Calcium ions rush into the neuron's cytoplasm. 3. An action potential depolarizes the membrane of the axon terminal. 4. The ligand-gated ion channels open. 5. The synaptic vesicles release neurotransmitter into the synaptic cleft. Which sequence of events is correct?
3 → 2 → 5 → 1 → 4
a Level: 2
4. Which of the following individuals would have the largest percentage of their bodyweight as water? A) a small 7-year-old female B) a lean 35-year-old male athlete C) a chunky 52-year-old male athlete D) a healthy 88-year-old male E) an adult female marathon runner
c Level: 1
43. Calcium balance is influenced by A) ADH and parathyroid hormone levels. B) ADH and aldosterone levels. C) parathyroid hormone and vitamin D levels. D) aldosterone and parathyroid hormone levels. E) insulin and glucagon
e Level: 2
44. Calcium's roles in the body include A) bone health. B) muscle contraction. C) blood clotting. D) action potentials in heart muscle. E) all of the above
a Level: 2
45. An increase in parathyroid hormone levels results in A) increased rate of bone resorption. B) increased rate of vitamin D degradation. C) increased concentration of potassium ions in the urine. D) increased rate of calcium ion excretion by the kidneys. E) decreased levels of blood calcium.
c Level: 2
46. Adequate calcium absorption from the GI tract depends on A) serum K levels. B) serum calcitonin levels. C) adequate amounts of vitamin D. D) the osmolality of the extracellular fluid. E) adequate amounts of vitamin C.
b Level: 2
49. The main regulator of serum phosphate levels is a transport process in the A) liver. B) kidneys. C) pancreas. D) small intestine. E) large intestine.
c Level: 2
50. A major complication of thyroid surgery is the accidental damaging or removal of the parathyroid glands. This damage or removal of the parathyroid glands can result in A) increased sodium retention. B) increased plasma volume. C) decreased plasma calcium. D) delayed healing. E) increased plasma calcium.
a Level: 1
52. Increased osmolality of the ECF A) increases thirst. B) inhibits ADH. C) increases renin secretion. D) increases aldosterone secretion. E) decreases thirst.
d Level: 2
58. Loss of a large volume of sweat will A) decrease the hematocrit. B) decrease ADH production. C) increase the blood pressure. D) increase the osmolality of body fluids. E) decrease the osmolality of body fluids.
a Level: 2
59. In which of the following situations does one see large volumes of dilute urine produced? A) ADH levels decrease B) renin levels increase C) aldosterone levels increase D) parathyroid hormone levels decrease E) ADH levels increase.
c Level: 2
6. Extracellular fluid has a A) higher protein content than intracellular fluid. B) higher potassium content that intracellular fluid. C) higher sodium content than intracellular fluid. D) higher magnesium content than intracellular fluid E) higher number of large organic molecules than intracellular fluid.
b Level: 2
67. As a result of hyperventilation, A) the body pH decreases. B) the plasma PCO2 level decreases. C) the kidney will increase the rate of hydrogen ion excretion. D) more bicarbonate ions are added to the plasma. E) the plasma PCO2 level increases.
d Level: 2
68. An increase in blood CO2 levels is followed by a(n) ____ in H+ ions and a(n) ____ in blood pH. A) decrease, decrease B) decrease, increase C) increase, increase D) increase, decrease E) increase, no change
a Level: 2
70. Mr. I.M.A. Wreck's plasma pH is 7.2. Which of the following indicates that the body is attempting to compensate and return the body pH to normal? A) an increase in respiration rate B) a decrease in respiration rate C) no change in respiration rate
c Level: 2
71. In renal compensation of acidosis, A) H+ secretion decreases; bicarbonate excretion increases. B) H+ secretion decreases; bicarbonate reabsorption increases. C) H+ secretion increases; bicarbonate reabsorption increases. D) H+ secretion increases; bicarbonate excretion increases. E) H+ secretion decreases; bicarbonate excretion decreases.
c Level: 1
73. The normal pH for blood plasma is A) 7.00. B) 7.25. C) 7.40. D) 7.55. E) 7.60.
c Level: 2
74. Once alkalosis has occurred, which of the following would you expect to happen? A) increased respiratory rate B) a plasma pH less than 7.40 C) retention of hydrogen ions by the kidney D) increased renal reabsorption of bicarbonate ions E) secretion of hydrogen ions by the kidney
b Level: 2
75. Hyposecretion of aldosterone would lead to A) increased secretion of hydrogen ions. B) decreased secretion of hydrogen ions. C) no change in secretion of hydrogen ions.
c Level: 2
77. A falling blood pH and a rising concentration of carbon dioxide due to emphysema, indicate A) metabolic acidosis. B) metabolic alkalosis. C) respiratory acidosis. D) respiratory alkalosis. E) none of the above
b Level: 3
83. The K+ level of 2.8 mEq/L indicates hypokalemia. Low plasma K+ levels will cause A) thirst. B) muscle weakness. C) increased body temperature. D) tremors, tetany, and convulsions. E) paralysis.
a Level: 2
9. The distribution of sodium and potassium ions between intracellular and extracellular compartments is A) potassium mainly intracellular; sodium mainly in extracellular. B) sodium mainly intracellular; potassium mainly in extracellular. C) little of either intracellular but large amounts of both extracellular. D) equal amounts of both ions, in both intracellular and extracellular fluids. E) none of the above
A human bone marrow cell, in prophase of mitosis, contains 46 chromosomes. How many chromatids does it contain?
92
10) What is the mode of action of aspirin and ibuprofen? A) They inhibit the synthesis of prostaglandins. B) They inhibit the release of nitric oxide, a potent vasodilator. C) They block paracrine signaling pathways. D) They stimulate the release of oxytocin. E) They stimulate the release of endorphins.
A
17) For hormones that homeostatically regulate cellular functions, A) negative feedback typically regulates hormone secretion. B) the circulating level of a hormone is held constant through a series of positive feedback loops. C) both lipid-soluble hormones and water-soluble hormones bind to intracellular protein receptors. D) endocrine organs release their contents into the bloodstream via specialized ducts. E) it is impossible to also have neural regulation of that system.
A
18) Nitric oxide and epinephrine A) both function as neurotransmitters. B) both function as steroid hormones. C) are both involved in the "fight-or-flight" response. D) bind the same receptors. E) both cause a reduction in the blood levels of glucose.
A
22) The hypothalamus controls the anterior pituitary by means of A) releasing hormones. B) second messengers. C) third messengers. D) antibodies. E) pyrogens.
A
34) Which of the following statements about endocrine glands is incorrect? A) The parathyroids regulate metabolic rate. B) The thyroid participates in blood calcium regulation. C) The pituitary participates in the regulation of the gonads. D) The adrenal medulla produces "fight-or-flight" responses. E) The pancreas helps to regulate blood sugar concentration.
A
36) Which hormone exerts antagonistic action to PTH (parathyroid hormone)? A) thyroxine B) epinephrine C) growth hormone D) calcitonin E) glucagon
A
40) The endocrine glands include the A) parathyroid glands. B) salivary glands. C) sweat glands. D) sebaceous glands. E) gallbladder.
A
52) Which combination of gland and hormone would be linked to winter hibernation and spring reproduction in bears? A) pineal gland, melatonin B) hypothalamus gland, melatonin C) anterior pituitary gland, gonadotropin-releasing hormone D) pineal gland, estrogen E) posterior pituitary gland, thyroid-stimulating hormone
A
58) Which of the following endocrine structures is (are) not controlled by a tropic hormone from the anterior pituitary? A) pancreatic islet cells B) thyroid gland C) adrenal cortex D) ovaries E) testes
A
6) Based on their effects, which pair below could be considered antagonistic? A) prostaglandin F and nitric oxide B) growth hormone and ecdysone C) endocrine and exocrine glands D) hormones and target cells E) neurosecretory cells and neurotransmitters
A
66) Oxytocin ________. A) release is an example of a positive feedback control mechanism B) exerts its most important effects during menstruation C) is an adenohypophyseal secretion D) controls milk production
A
69) Gonadocorticoid(s) ________. A) production by the adrenal gland is insignificant compared with sex hormone release from the gonads during late puberty B) synthesized by the adrenal medulla are primarily androgens C) hypersecretion can result in adrenogenital syndrome, also called feminization D) secretion inhibition is highly dependent on a negative feedback loop involving ACTH
A
72) The ability of a specific tissue or organ to respond to the presence of a hormone is dependent on ________. A) the presence of the appropriate receptors on the cells of the target tissue or organ B) the membrane potential of the cells of the target organ C) nothingall hormones of the human body are able to stimulate any and all cell types because hormones are powerful and nonspecific D) the location of the tissue or organ with respect to the circulatory path
A
79) Thyroid hormone (a small iodinated amine) enters target cells in a manner similar to ________. A) steroid hormones, because both diffuse easily into target cells B) glucagon, because the structure of glucagon is similar to that of thyroid hormone C) growth hormone, because the thyroid works synergistically with thyroid hormone D) insulin, because insulin is a small peptide
A
D. cAMP
A "second messenger" for hormone response is A. adenylate cyclase B. ATP C. protein kinase D. cAMP
People with type II diabetes mellitus have defective insulin receptors that cannot respond to insulin properly. Relative to normal individuals, what would be the effect on blood glucose levels under conditions of chronic stress that kept blood cortisol levels high? There would be _____>
A greater increase in blood glucose levels in individuals with type II diabetes mellitus than in normal individuals.
Which of these structures is a separate generation from the plant sporophyte?
A male gametophyte within a pollen grai
osmoreceptors
A person working outside in the hot sun can perspire a great deal. This increase in perspiration results in an increase in water loss from the body. Increased water loss causes the serum osmolality to increase. This increased osmolality is "sensed" by the kidneys. osmoreceptors. cerebral cortex. anterior pituitary.
18) Which organism(s) has excretory structures known as protonephridia? A) flatworms B) earthworms C) insects D) vertebrates E) both C and D
A) flatworms
36) Which one of the following structures is found in birds and mammals but not in other vertebrates? A) juxtamedullary nephrons B) nephrons C) urethra D) ureter E) Bowman's capsule
A) juxtamedullary nephrons
34) Which structure descends deep into the renal medulla only in juxtamedullary nephrons? A) loop of Henle B) collecting duct C) Bowman's capsule D) proximal convoluted tubule E) glomerulus
A) loop of Henle
8) The digestion and utilization of which nutrient creates the greatest need for osmoregulation by the kidneys? A) protein B) starch C) fat D) oil E) cellulose
A) protein
25) Which of the following normally contains blood? A) vasa recta B) Bowman's capsule C) loop of Henle D) proximal tubule E) collecting duct
A) vasa recta
ADH and RAAS work together in maintaining osmoregulatory homeostasis through which of the following ways? ADH regulates the osmolarity of the blood by altering renal reabsorption of water, and RAAS maintains the osmolarity of the blood by stimulating Na+ and water reabsorption. ADH regulates the osmolarity of the blood and RAAS regulates the volume of the blood. by combining at the receptor sites of proximal tubule cells, where reabsorption of essential nutrients takes place. ADH and RAAS work antagonistically; ADH stimulates water reabsorption during dehydration and RAAS causes increased excretion of water when it is in excess in body fluids. both stimulate the adrenal gland to secrete aldosterone, which increases both blood volume and pressure via its receptors in the urinary bladder.
ADH regulates the osmolarity of the blood by altering renal reabsorption of water, and RAAS maintains the osmolarity of the blood by stimulating Na+ and water reabsorption.
Which of the following statements about endocrine glands and the hormones they produce is true?
Aldosterone produced by the adrenal glands controls the reabsorption of sodium ions by the kidneys.
The adrenal glands produce
Aldosterone.
increase heart rate, increase blood pressure, decrease gastric tract motility
An injection of epinephrine would increase heart rate, increase blood pressure, increase gastric tract motility. decrease heart rate, decrease blood pressure, increase gastric tract motility. increase heart rate, increase blood pressure, decrease gastric tract motility. decrease heart rate, decrease gastric motility, increase blood pressure.
Which of the following best explains why androgen abuse among males may lead to decreased sperm production?
Androgens can instruct the pituitary to decrease secretion of luteinizing hormone.
Identify the correct statement(s) about glial cells and their functions.
Astrocytes participate in the formation of the blood-brain barrier.
180 liters
At the rate of 125 ml of filtrate/minute, estimate the amount of filtrate formed in 24 hours. 45 liters 90 liters 125 liters 180 liters
) In humans, no new primary spermatocytes are formed after childbirth. (T,F) In humans, no new primary oocytes are formed after childbirth. (T,F)
F; T
40) What happens when beta cells of the pancreas release insulin into the blood? A) Blood glucose levels rise to a set point and stimulate glucagon release. B) Body cells take up more glucose. C) The liver breaks down glycogen to glucose. D) Alpha cells are stimulated to release glucose into the blood. E) Both B and D are correct.
B
44) Which of the following glands is controlled directly by the hypothalamus or central nervous system but not the anterior pituitary? A) ovary B) adrenal medulla C) adrenal cortex D) testis E) thyroid
B
45) When the beta cells of the pancreas release insulin into the blood, A) the blood glucose levels rise to a set point and stimulate glucagon release. B) the skeletal muscles and the adipose cells take up glucose at a faster rate. C) the liver catabolizes glycogen. D) the alpha cells of the pancreas release glucose into the blood. E) the kidneys begin gluconeogenesis.
B
47) Which of the following hormones is (are) secreted by the adrenal gland in response to stress and promote(s) the synthesis of glucose from noncarbohydrate substrates? A) glucagon B) glucocorticoids C) epinephrine D) thyroxine E) ACTH
B
49) Which of the following hormone sequences is correct? A) LH → FSH → adrenal glands B) GnRH → FSH → ovaries C) CRH → ACTH → FSH → thyroid gland D) CRH → LH → testes E) GnRH → FSH → LH → pineal gland
B
74) The neurohypophysis or posterior lobe of the pituitary gland is not a true endocrine gland because ________. A) it is unable to function as an endocrine tissue because it is actually part of the neural system due to its location B) it is only a hormone storage area that receives hormones from the hypothalamus for release C) it is strictly a part of the neural system and has little or nothing to do with hormonal release D) embryonically it was an endocrine tissue, but in the adult human it is no longer functional
B
75) An example of antagonistic hormones controlling homeostasis is A) thyroxine and parathyroid hormone in calcium balance. B) insulin and glucagon in glucose metabolism. C) progestins and estrogens in sexual differentiation. D) epinephrine and norepinephrine in fight-or-flight responses. E) oxytocin and prolactin in milk production.
B
87) The most important regulator of electrolyte concentrations in extracellular fluids is ________. A) glucagon B) aldosterone C) insulin D) cortisol
B
97) In circumstances where the body requires prolonged or increased levels of a hormone, the DNA of target cells will specify the synthesis of more receptors on the surface of the cells of the target organ. This is known as ________. A) a reaction to a stressor B) up-regulation C) cellular affinity D) the cell's sensitivity reaction
B
49) Which statement is true about marine fishes? A) Compared to marine fishes, freshwater fishes have fewer glomeruli. B) The kidneys of marine fishes excrete little urine. C) Marine fishes lack proximal tubules. D) Marine fishes secrete uric acid to conserve water. E) Their kidneys produce filtrate at high rates.
B) The kidneys of marine fishes excrete little urine.
1) A marine sea star was mistakenly placed in freshwater and it died. What is the most likely explanation for its death? A) The sea star was stressed and needed more time to adapt to new conditions. B) The sea star is hypertonic to the freshwater, and it could not osmoregulate. C) The osmoregulatory system of the sea star could not handle the change in ionic content presented by the freshwater. D) The contractile vacuoles used to regulate water content ruptured in the freshwater. E) The cells of the sea star dehydrated and lost the ability to metabolize.
B) The sea star is hypertonic to the freshwater, and it could not osmoregulate.
31) Which structure passes urine to the renal pelvis? A) loop of Henle B) collecting duct C) Bowman's capsule D) proximal tubule E) glomerulus
B) collecting duct
2) Organisms categorized as osmoconformers are most likely A) terrestrial. B) marine. C) amphibious. D) found in freshwater streams. E) found in freshwater lakes.
B) marine.
7) All of the following represent adaptations by terrestrial animals to drying conditions except A) anhydrobiosis. B) salt glands. C) efficient kidneys. D) impervious surfaces. E) increased thirst.
B) salt glands.
13) Which of the following is not a function of the liver? A) storage of glycogen B) secretion of urea C) production of plasma proteins D) removal of glucose from the blood E) detoxification of chemical poisons in the blood
B) secretion of urea
47) Which of the following activities would initiate an osmoregulatory adjustment brought about primarily through the renin-angiotensin-aldosterone system? A) sleeping B) spending several hours mowing the lawn on a hot day C) eating a bag of potato chips D) eating a pizza with olives and pepperoni E) drinking several glasses of water
B) spending several hours mowing the lawn on a hot day
14) The advantage of excreting wastes as urea rather than as ammonia is that A) urea can be exchanged for Na+. B) urea is less toxic than ammonia. C) urea requires more water for excretion than ammonia. D) urea does not affect the osmolar gradient. E) less nitrogen is removed from the body.
B) urea is less toxic than ammonia.
In a laboratory experiment with three groups, one group of people drinks pure water, a second group drinks an equ al amount of beer, and a third group drinks an equal amount of concentrated salt solution all during the same period. Their urine production is monitored for several hours. At the end of the measurement period, which group will have produced the greatest volume of urine and which group the least?
Beer the most, salt solution the least.
80%
By the time filtrate reaches the tip of the loop of Henle, _____ of the filtrate volume has been reabsorbed. 65% 75% 80% 95%
11) Different body cells can respond differently to the same peptide hormones because A) different target cells have different sets of genes. B) each cell converts that hormone to a different metabolite. C) a target cell's response is determined by the components of its signal transduction pathways. D) the circulatory system regulates responses to hormones by routing the hormones to specific targets. E) the hormone is chemically altered in different ways as it travels through the circulatory system.
C
13) Why is it that some body cells respond differently to the same peptide hormones? A) Different target cells have different genes. B) Each cell knows how it fits into the body's master plan. C) A target cell's response is determined by the product of a signal transduction pathway. D) The circulatory system regulates responses to hormones by routing the hormones to specific targets. E) The hormone is chemically altered in different ways as it travels through the circulatory system.
C
21) During mammalian labor and delivery, the contraction of uterine muscles is enhanced by oxytocin. This is an example of A) a negative feedback system. B) a hormone that acts in an antagonistic way with another hormone. C) a hormone that is involved in a positive feedback loop. D) signal transduction immediately changing gene expression in its target cells. E) the key role of the anterior pituitary gland in regulating uterine contraction.
C
21) The endocrine system and the nervous system are structurally related. Which of the following cells best illustrates this relationship? A) a neuron in the spinal cord B) a steroid-producing cell in the adrenal cortex C) a neurosecretory cell in the hypothalamus D) a brain cell in the cerebral cortex E) a cell in the pancreas that produces digestive enzymes
C
23) Short blood vessels connect two capillary beds lying in which of the following? A) hypothalamus and thalamus B) anterior pituitary and posterior pituitary C) hypothalamus and anterior pituitary D) posterior pituitary and thyroid gland E) anterior pituitary and adrenal gland
C
24) The interrelationships between the endocrine and the nervous systems are especially apparent in A) a neuron in the spinal cord. B) a steroid-producing cell in the adrenal cortex. C) a neurosecretory cell in the hypothalamus. D) a brain cell in the cerebral cortex. E) a cell in the pancreas that produces digestive enzymes.
C
29) Prolactin stimulates mammary gland growth and development in mammals and regulates salt and water balance in freshwater fish. Many scientists think that this wide range of functions indicates that prolactin A) is a nonspecific hormone. B) has a unique mechanism for eliciting its effects. C) is an evolutionarily conserved hormone. D) is derived from two separate sources. E) interacts with many different receptor molecules.
C
69) Steroid and peptide hormones typically have in common A) the building blocks from which they are synthesized. B) their solubility in cell membranes. C) their requirement for travel through the bloodstream. D) the location of their receptors. E) their reliance on signal transduction in the cell.
C
74) Which of the following hormones is incorrectly paired with its action? A) oxytocin—stimulates uterine contractions during childbirth B) thyroxine—stimulates metabolic processes C) insulin—stimulates glycogen breakdown in the liver D) ACTH—stimulates the release of glucocorticoids by the adrenal cortex E) melatonin—affects biological rhythms, seasonal reproduction
C
45) What would account for increased urine production as a result of drinking alcoholic beverages? A) increased aldosterone production B) increased blood pressure C) decreased amount of antidiuretic hormone (ADH) D) increased reabsorption of water in the proximal tubule E) the osmoregulator cells of the brain increasing their activity
C) decreased amount of antidiuretic hormone (ADH)
59) The body fluids of freshwater crustaceans generally have a lower osmolarity than the body fluids of their nearest marine crustacean relatives. Which of the following is a benefit of reduced osmolarity of body fluids in freshwater crustaceans? A) an increase in the rate of water flow into the body fluids B) a decrease in the rate of water loss to the surrounding environment C) a reduction in energy expenditures for osmoregulation D) an increase in the rate of salt loss to the surrounding environment E) a decrease in the rate of salt gain from the environment
C) a reduction in energy expenditures for osmoregulation
17) What is the process called by which materials are returned to the blood from the nephron fluid? A) filtration B) ultrafiltration C) selective reabsorption D) secretion E) active transport
C) selective reabsorption
11) Which of the following is true of urea? It is A) insoluble in water. B) more toxic to human cells than ammonia. C) the primary nitrogenous waste product of humans. D) the primary nitrogenous waste product of most birds. E) the primary nitrogenous waste product of most aquatic invertebrates.
C) the primary nitrogenous waste product of humans.
T cells of the immune system include: A. lymphocytes, macrophages, and dendritic cells B. plasma, antigen-presenting, and memory cells. C. cytotoxic and helper cells D. class I MHC, class II MHC, and memory cells. E. CD4, CD8, and plasma cells
C. cytotoxic and helper cells
What structure in female humans is analogous to the sensitive tissues of the penis?
Clitoris
102) How do glucocorticoids enable the body to deal appropriately with stress? A) by stimulating the pancreas to release insulin B) by decreasing the heart rate, thus decreasing blood pressure C) by blocking the neurotransmitters that prepare the body for the stress response D) by increasing blood glucose, fatty acid, and amino acid levels and enhancing blood pressure
D
5) Substance X is secreted by one cell, travels a short distance through interstitial fluid, and produces an effect in a cell immediately adjacent to the original secreting cell. All of the following terms could describe this substance except A) nitric oxide. B) neurotransmitter. C) prostaglandin. D) pheromone. E) growth factor.
D
60) Which process in the nephron is least selective? A) secretion B) reabsorption C) active transport D) filtration E) salt pumping by the loop of Henle
D) filtration
20) Which of the following mechanisms for osmoregulation or nitrogen removal is incorrectly paired with its corresponding animal? A) metanephridium-earthworm B) Malpighian tubule-insect C) kidney-frog D) flame bulb-snake E) direct cellular exchange-marine invertebrate
D) flame bulb-snake
51) The outer part of the kidney is the A) medulla. B) nephron. C) lacteal. D) cortex. E) Bowman's capsule.
D) cortex.
41) Which one of the following, if present in a urine sample, would likely be caused by trauma? A) amino acids B) glucose C) salts D) erythrocytes E) vitamins
D) erythrocytes
23) The transfer of fluid from the glomerulus to Bowman's capsule A) results from active transport. B) transfers large molecules as easily as small ones. C) is very selective as to which small molecules are transferred. D) is mainly a consequence of blood pressure force-filtering the fluid. E) usually includes the transfer of red blood cells to the nephron tubule.
D) is mainly a consequence of blood pressure force-filtering the fluid.
3) The body fluids of an osmoconformer would be ________ with its ________ environment. A) hypertonic; freshwater B) isotonic; freshwater C) hyperosmotic; saltwater D) isoosmotic; saltwater E) hypoosmotic; saltwater
D) isoosmotic; saltwater
55) Unlike an earthworm's metanephridia, a mammalian nephron A) is intimately associated with a capillary network. B) forms urine by changing the composition of fluid inside the tubule. C) functions in both osmoregulation and the excretion of nitrogenous wastes. D) processes blood instead of coelomic fluid. E) has a transport epithelium.
D) processes blood instead of coelomic fluid.
56) Which of the following is not a normal response to increased blood osmolarity in humans? A) increased permeability of the collecting duct to water B) increased thirst C) release of ADH by the pituitary gland D) production of more dilute urine E) reduced urine production
D) production of more dilute urine
Under certain conditions, cells produce a metabolic byproduct called (DPG). Which of the following would support the hypothesis that DPG helps increase oxygen unloading from tissues?
DPG decreases percentage saturation of hemoglobin with oxygen at a PO2 of 30mm Hg.
20) Hormones that promote homeostasis A) are not found as members of antagonistic signaling mechanisms. B) travel to target cells without passage in the plasma. C) utilize receptors that bind any hormone. D) initiate signal transduction in the target cell without binding to receptors. E) usually operate as part of a negative feedback system.
E
28) The hypothalamus A) functions only as an endocrine target, by having lots of receptors on its cells. B) functions only in neuronal transmission. C) does not have any hormone receptors on its cells. D) secretes tropic hormones that act directly on the gonads. E) includes neurosecretory cells that terminate in the posterior pituitary.
E
39) Blood samples taken from an individual who had been fasting for 24 hours would have which of the following? A) high levels of insulin B) high levels of glucagon C) low levels of insulin D) low levels of glucagon E) both B and C
E
43) Which of the following are synthesized from the amino acid tyrosine? A) epinephrine B) catecholamines C) norepinephrine D) A and B only E) A, B, and C
E
57) The high osmolarity of the renal medulla is maintained by all of the following except A) diffusion of salt from the ascending limb of the loop of Henle. B) active transport of salt from the upper region of the ascending limb. C) the spatial arrangement of juxtamedullary nephrons. D) diffusion of urea from the collecting duct. E) diffusion of salt from the descending limb of the loop of Henle.
E) diffusion of salt from the descending limb of the loop of Henle.
21) Which of the following excretory systems is partly based on the filtration of fluid under high hydrostatic pressure? A) flame-bulb system of flatworms B) protonephridia of rotifers C) metanephridia of earthworms D) Malpighian tubules of insects E) kidneys of vertebrates
E) kidneys of vertebrates
35) All of the following are functions of the mammalian kidney except A) water reabsorption. B) filtration of blood. C) excretion of nitrogenous waste. D) regulation of salt balance in the blood. E) production of urea as a waste product of protein catabolism.
E) production of urea as a waste product of protein catabolism.
48) Hormones involved in the production of urine include all of the following except A) aldosterone. B) angiotensin. C) ADH. D) atrial natriuretic factor. E) secretin.
E) secretin.
3) The most abundant solute in urine is A) glucose. B) water. C) plasma proteins. D) sodium chloride. E) urea (and other nitrogenous wastes).
E) urea (and other nitrogenous wastes).
58) Select the pair in which the nitrogenous waste is incorrectly matched with the benefit of its excretion. A) urea—low toxicity relative to ammonia B) uric acid—can be stored as a precipitate C) ammonia—very soluble in water D) uric acid—minimal loss of water when excreted E) urea—very insoluble in water
E) urea—very insoluble in water
If a eukaryotic cell is in the G1 phase of the cell cycle, which statement about the cell's chromosomes must be correct?
Each chromosome is made of a complex of DNA and associated proteins.
Closer Look at Glycolyis
Energy Investment 1) Hexokinase transfers a phosphate group from ATP to glucose, making it more chemically reactive. The charge on the phosphate also traps the sugar in the cell 2) Glucose 6-phosphate is converted to its isomer, fructose 6-phosphate by phosphogluco-isomerase 3) Phosphofructokinase transfers a phosphate group from ATP to the opposite end of the sugar, investing a second molecule of ATP. This is a key step for regulation of glycolysis 4) Fructose 1,6-bisphosphate is cleaved by aldolase into two different three-carbon sugars (isomers: Dihydroxyacetone phosphate and Glyceraldehyde 3-phosphate). The energy payoff phase occurs after glucose is split into two three-carbon sugars so the coefficient 2 precedes all molecules in this phase Energy Payoff 5) Isomerase catalyzes the reversible conversion between the two isomers. This reaction never reaches equilibrium; Glyceraldehyde 3-phosphate is used as the substrate of the next reaction as fast as it forms 6) Triose phosphate dehydrogenase catalyzes two sequential reactions. First the sugar is oxidized by the transfer of electrons to NAD+, forming NADH. Second, the energy released from this this exergonic redox reaction is used to attach a phosphate group to the oxidized substrate, making a product of very high potential energy 7) The phosphate group added in the previous step is transferred to ADP (substrate level phosphorylation) in an exergonic reaction. The carbonyl group of a sugar has been oxidized to the carboxyl group of an organ acid (3-phosphoglycerate) 8) Phosphoglyceromutase relocates the remaining phosphate group 9) Enolase causes a double bond to form in the substrate by extracting a water molecule, yielding phosphoenolpyruvate (PEP), a compound with a very high potential energy, 2H2O leave here 10) The phosphate group is transferred from PEP to ADP by Pyruvate kinase (a second example of substrate level phosphorylation) forming pyruvate
B
Filtrate is formed as fluid is forced through the walls of the glomerulus and, initially, collects in the structure indicated by the letter
To become bound to hemoglobin for transport in a mammal, atmospheric molecules of oxygen must cross ____.
Five membranes-in and out of the cell lining the lung, in and out of the endothelial cell lining and alveolar capillary, and into the red blood cell- to bind with hemoglobin.
Adrenocorticotropic hormone (ACTH) triggers the release of _____ in response to stress
Glucocorticoids; in response to stress, ACTH stimulates the adrenal cortex to secrete glucocorticoids.
) In humans, puberty in females is controlled by release of ______ from the hypothalamus.
Gonadotropin-releasing hormone (GnRH)
The oxygen content of water increases linearly with an increase in oxygen partial pressure, while the oxygen content of blood increases in a sigmoidal fashion. Why?
Hemoglobin shows cooperative binding.
What is the driving force for the filtration of blood by the renal corpuscle?
Higher pressure in glomerular capillaries than in the surrounding Bowman's capsule.
How are sister chromatids and homologous chromosomes different from each other?
Homologous chromosomes contain the same gene loci but may have different alleles of a particular gene. Sister chromatids are identical copies of each other produced during DNA replication.
neurohormones of the hypothalamus.
Hormone secretion by the anterior pituitary is controlled by hormones of the thalamus. neurohormones of the hypothalamus. itself (anterior pituitary) because it is the master gland of the body. the overall rate of metabolism.
D. cerebral spinal fluid changes
Hormone secretion is regulated by all but which of the following? A. neural signals B. blood chemistry changes C. other hormones D. cerebral spinal fluid changes
action potentials from hypothalamic neurosecretory cells.
Hormones are released from the posterior pituitary when posterior pituitary cells are stimulated by hypothalamic releasing hormones. hormones from the anterior pituitary. action potentials from hypothalamic neurosecretory cells. the primary capillary network.
Which of the following is not an accurate statement?
Hormones of the same chemical class usually have the same function.
D. stimulates protein synthesis and inhibits protein breakdown
Human growth hormone, through the action of insulinlike growth factors, A. stimulates testes to produce sperm and stimulates growth of the corpus luteum B. regulates the amount of calcium ions in the blood C. stimulates reabsorption of both Na+ and K+ D. stimulates protein synthesis and inhibits protein breakdown
proximal and distal tubules.
Hydrogen ions are secreted into the filtrate by both the proximal and distal tubules. collecting duct and Bowman's capsule. loop of Henle and the distal tubule. proximal tubule and the loop of Henle.
nursing a baby
Oxytocin release is stimulated by nursing a baby. increased blood pressure. increased urine output. a hypothalamic releasing hormone.
1560 ml.
If daily water output from the body is 2600 ml, you would expect the daily urine output to be 1040 ml. 1300 ml. 1560 ml. 1820 ml.
C. decreased secretion of antidiuretic hormone
If you drank a liter of water very quickly, the result would be A. increased secretion of antidiuretic hormone B. decreased secretion of oxytocin C. decreased secretion of antidiuretic hormone D. increased secretion of oxytocin
mast cells
Immune cells that function to detect foreign substances in tissue spaces; initate local inflammatory responses They do not ciculate in the blood Play an important role in allergic responses
Which of the following is a true statement regarding species diversity and taxonomic diversity? 1) the variety of species in a given area represents taxonomic diversity. 2) In species diversity, the number of animals in a particular lineage is important. 3) In taxonomic diversity, the evolutionary relationships of species in a lineage are important.
In taxonomic diversity, the evolutionary relationships of species in a lineage are important.
C. a paracrine
In the stomach, the release of histamine by mast cells stimulates nearby cells to secrete hydrochloric acid). Histamine can therefore be classified as A. an endocrine B. an exocrine C. a paracrine D. an autocrine
What causes the falling phase of the action potential? Select the best answer.
Inactivation of voltage-gated sodium channels and the opening of voltage-gated potassium channels
increased blood osmolality
Increased ADH secretion could be stimulated by which of the following situations? increased renal blood flow increased blood osmolality increased atrial natriuretic hormone production increased blood pressure
what compound directly stimulates adrenal cortex to secrete aldosterone?
Increased Angiotensin 2 (converted from Angiotensin 1 by ACE in lungs)
B. a lower concentration of protein anions than plasma
Intracellular fluid has A. a higher concentration of potassium than interstitial fluid B. a lower concentration of protein anions than plasma C. a higher concentration of bicarbonate than plasma D. approximately the same concentrations of sodium, chloride, and potassium as plasma
Juxtamedullary nephrons can concentrate salt effectively in the renal medulla because of their long _____.
Loops of Henle
(Relation to Fick's Law) Constant delivery of deoxygenated blood to alveoli maintains a steep partial pressure gradient, favoring diffusion of oxygen into the body.
P2-P1 is high.
Tissues are typed before an organ transplant to make sure that the _____ of donor and recipient match as closely as possible.
MHC (major histocompatibility complex) proteins
proximal convoluted tubule
Most water is reabsorbed from the filtrate in the proximal convoluted tubule. descending loop of Henle. ascending loop of Henle. distal convolute tubule.
Which of the following activities would initiate an osmoregulatory adjustment brought about primarily through the renin-angiotensin-aldosterone (RAAS) system?
Mowing a lawn for several hours on a hot day
Which of the following statements about the pituitary gland is false? It produces hormones that control the menstrual cycle. The posterior portion is an extension of the hypothalamus. The anterior pituitary is connected to the hypothalamus by blood vessels Neurosecretory cells produce hormones that are stored in the anterior pituitary.
Neurosecretory cells produce hormones that are stored in the anterior pituitary; This statement is false; neurosecretory cells produce hormones that are stored in the posterior pituitary.
each nephron has at least two capillary networks.
One feature of renal blood circulation that makes it unique is that there is a double set of venules. blood flows from arterioles into venules. blood flows from venules into arterioles. each nephron has at least two capillary networks
decreases
Overall, PTH _____ blood phosphate levels. increases decreases has no effect on
) When a pregnant woman goes into labor, the hormone ______ stimulates smooth muscle cells in the uterine wall to being contractions.
Oxytocin
Parathyroid hormone (PTH) is released by the _____ gland. It helps to control _____ levels in the blood.
Parathyroid; calcium
Cephalization, the clustering of neurons and interneurons in the anterior part of the animal, is apparent in
Planaria
Select the correct statement about the life cycle of a fern.
Plant gametophytes are haploid multicellular bodies.
protein
Plasma contains a much greater concentration of _____ than the glomerular filtrate. urea water protein sodium ions
aldosterone.
Potassium levels in the body are regulated by ADH. PTH. calcitonin. aldosterone
) Follicle stimulating hormone (FSH) cannot initiate a new cycle of follicular development during the luteal phase of the human menstrual cycle because its synthesis is inhibited by _____.
Progesterone
metabolic alkalosis.
Prolonged vomiting of stomach contents will result in metabolic acidosis. metabolic alkalosis. respiratory acidosis. respiratory alkalosis.
A. are eicosanoids that act as local hormones in most body tissues.
Prostaglandins A. are eicosanoids that act as local hormones in most body tissues. B. stimulate increased intracellular levels of cAMP by activating adenylate cyclase C. combine with cytoplasmic receptors and directly affect host cell DNA D. work with protein kinase to deactivate cAMP and thus stimulate cells to make new and different proteins
The route of blood flow through the kidney
Renal artery - segmental arteries - Interlobar arteries - arcuate arteries - interlobular arteries - afferent arterioles - glomeruli - efferent arterioles - peritubular capillaries - vasa recta - peritubular venules - interlobular veins - arcuate veins - interlobar veins - renal vein
African lungfish, which are often found in small stagnant pools of fresh water, produce urea as a nitrogenous waste. What is the advantage of this adaptation? Urea makes lungfish tissue hypoosmotic to the pool. Urea takes less energy to synthesize than ammonia. Urea forms an insoluble precipitate. The highly toxic urea makes the pool uninhabitable to potential competitors. Small stagnant pools do not provide enough water to dilute the toxic ammonia.
Small stagnant pools do not provide enough water to dilute the toxic ammonia.
distal convoluted tubule and collecting ducts
Some lung cancers secrete large amounts of ADH. This causes increased water reabsorption in the proximal convoluted tubule. loop of Henle. distal convoluted tubule and collecting ducts. calyces.
Which of the following is the most likely explanation for the lack of a filter blocking the passage of alcohol between the maternal and fetal circulations in humans?
Such a barrier would probably also block important molecules that need to be passed to the fetus.
) The polypeptide hormone PYY(3-36) ______ the appetite. Incretins _____ the appetite.
Suppresses; suppress
greater than
The amount of epinephrine secreted by the adrenal medulla is ____ the amount of norepinephrine secreted by the adrenal medulla. greater than less than equal to
How does the adrenal gland respond to stress?
The adrenal medulla secretes epinephrine and norepinephrine in response to short-term stress.
) _______ derived from non-brain tissues.
The anterior pituitary gland is
Follicle-stimulating hormone (FSH) and leutinizing hormone (LH) are made by
The anterior pituitary gland.
You just received a freshwater aquarium as a gift and decide to add more fish. When you get to the pet store, you find that the most beautiful fish are saltwater animals, but you decide to buy them anyway. What will happen when you put your expensive saltwater fish in your freshwater aquarium?
The cells of the fish will take up too much water, and the fish will die.
vary in their permeability to water relative to the amounts of ADH present.
The collecting ducts and distal convoluted tubules reabsorb glucose. collect filtrate from Bowman's capsule. actively transport sodium ions but not chloride ions. vary in their permeability to water relative to the amounts of ADH present.
podocytes, capillary epithelium, and basement membrane.
The filtration membrane consists of the capillary epithelium, podocytes, and macula densa. podocytes, basement membrane, and macula densa. basement membrane, capillary epithelium, and macula densa. podocytes, capillary epithelium, and basement membrane.
posterior pituitary
The hypothalamohypophyseal tract connects the hypothalamus to the anterior pituitary. posterior pituitary. pars distalis. adenohypophysis
How is the production of hormones such as thyroxine and estrogen regulated?
The hypothalamus directs the anterior pituitary to produce hormones that then stimulate or inhibit the production of these hormones.
have long loops of Henle.
The juxtamedullary nephrons have long loops of Henle. are found next to the renal capsule. comprise 85% of all nephrons. have their renal corpuscles located in the medulla.
B. CRH, TRH, and GHRH
The releasing hormones of the hypothalamus responsible for initiating the resistance reaction phase of the GAS are A. GNRH and PIH B. CRH, TRH, and GHRH C. oxytocin and ADH D. PRH, FSH, and IGFs
C. human growth hormone (hGH)
The most abundant anterior pituitary hormone is A. follicle-stimulating hormone (FSH) B. thyroid-stimulating hormone (TSH) C. human growth hormone (hGH) D. adrenocorticotropic hormone (ACTH)
D. protein buffer system
The most abundant buffer system inside body cells and in plasma is the A. carbonic acid buffer system B. phosphate buffer system C. sodium bicarbonate buffer system D. protein buffer system
renal cortex
The most superficial region of the internal kidney is the
Which of the following statements comparing respiration in fish and in mammals is correct? 1) A countercurrent exchange mechanism between the respiratory medium and blood flow is seen in mammals but not fish. 2) The respiratory medium for fish carries more oxygen than the respiratory medium of mammals. 3) In blood, oxygen is primarily transported by plasma in fish, but by red blood cells in mammals. 4) The movement of the respiratory medium in mammals is bidirectional, but in fish it is unidirectional.
The movement of the respiratory medium in mammals is bidirectional, but in fish it is unidirectional.
What happens when a resting neuron's membrane depolarizes?
The neuron's membrane voltage becomes more positive.
C. excrete hydrogen ions in the urine
The only way the body can get rid of the huge acid load produced by metabolic reactions is to A. increase the concentration of bicarbonate ions B. breathe faster and more deeply C. excrete hydrogen ions in the urine D. increase the concentration of proteins in the plasma
renal fraction.
The part of the cardiac output that passes through the kidneys is the renal fraction. filtration fraction. clearance fraction. glomerular flow rate
Which of the following statements is correct ? Select one: a. The anterior lobe of the pituitary is nervous tissue that connects directly to the brain whereas the posterior pituitary is derived from non-neural tissues b. The posterior pituitary gland stores and secretes oxytocin and antidiuretic hormone (ADH) that are synthesized in the hypothalamus c. The posterior lobe of the pituitary operates independently of the brain whereas the anterior lobe is directly dependent on brain activity d. The anterior lobe of the pituitary receives neuronal impulses from brain cells whereas the posterior lobe receives blood-borne hormones
The posterior pituitary gland stores and secretes oxytocin and antidiuretic hormone (ADH) that are synthesized in the hypothalamus correct
Due to its system of air sacs connected to the lungs, the respiratory system of birds is arguable the most effective respiratory system of all air-breathers. Upon inhalation, air first flows into posterior air acs, then into the lungs, and then into anterior air sacs on the way to being exhaled. Thus, there is one-way flow of air through the lungs, along thousands of tubules called parabronchi. If the inner lining of the air sacs is neither thin nor highly vascularized, then what can be inferred about the air sacs?
They are not efficient sites of gas exchange between air and blood.
How are materials returned to the blood from the filtrate?
Through selective reabsorption.
Predict how a woman's hypothyroidism would affect prolactin levels in her body
Thyroid hormones level decrease, TRH levels increase, and PRL levels increase
) The anterior pituitary gland produces
Thyroid-stimulating hormone (TSH).
1, 3, 2, 4
Trace the path of a red blood cell from the renal artery to the glomerulus: (1) interlobar artery (2) interlobular artery (3) arcuate artery (4) afferent arteriole 1, 2, 3, 4 1, 4, 2, 3 1, 3, 2, 4 2, 1, 3, 4
A series of hydrophobic sides chains will congregate together as a protein folds in an aqueous solution and be stabilized by _____.
Van der Waals interactions.
Which male reproductive structures are responsible for the transport and delivery of sperm?
Vas deferens, urethra, and penis.
Which of the following is the correct sequence of blood flow in birds and mammals? 1) Right atrium, pulmonary artery, left atrium, ventricle 2) Vena cava, right atrium, right ventricle, pulmonary artery 3) Vena cava, right atrium, right ventricle, pulmonary vein 4) Left ventricle, aorta, lungs, systemic circulation 5) Pulmonary vein, left atrium, left ventricle, pulmonary circquit
Vena cava, right atrium, right ventricle, pulmonary artery
An important group of peripheral membrane proteins are enzymes such as the phospholipases that cleave the head groups of phospholipids. What properties must these enzymes exhibit?
Water solubility.
a small 7-year-old female
Which of the following individuals would have the largest percentage of their bodyweight as water? a small 7-year-old female a lean 35-year-old male athlete a chunky 52-year-old male athlete a healthy 88-year-old male
B. down-regulation
When an excess of a hormone is present the number of target cell receptors may decrease. This change is called A. up-regulation B. down-regulation C. adaptation D. accommodation
C. norepinephrine
Which chemical acts both as a neurotransmitter in some locations and as a hormone in other locations? A. insulin B. thyroxine C. norepinephrine D. acetylcholine
Angiotensin II, Aldosterone, ADH, Atrial natriuretic peptide, and Parathyroid hormone
Which of the following hormones affect Na+, CL-, Ca^2+, and water reabsorption and K+ secretion by the renal tubules
B. T3
Which of the following hormones influence metabolism of most somatic cells? A. PRL B. T3 C. FSH D. thymosin
lipotropins
Which of the following hormones promotes the breakdown of fatty acids? lipotropins somatotropins gonadotropins thyrotropins
B. prolactin
Which of the following hormones requires a releasing hormone from the hypothalamus for its secretion? A. oxytocin B. prolactin C. antidiuretic hormone D. calcitonin
The blood-brain barrier
is formed by tight junctions.
pars distalis
Which of the following is a subdivision of the anterior pituitary? pars nervosa pars distalis pars hypothalamus pars infundibuli
decreased urine volume
Which of the following is an example of water conservation by the body? diarrhea perspiration decreased water intake decreased urine volume
increased plasma osmolality
Which of the following situations increases the number of action potentials to the supraoptic region of the hypothalamus? increased blood velocity decreased renin production increased plasma osmolality decreased aldosterone secretion
They act by affecting the transcription of genes.
Which of the following statements about lipid-soluble hormones is true? -They bind to receptors on the plasma membrane. -They bind to DNA as soon as they enter a cell. -They act by affecting the transcription of genes. -They act by producing second messengers.
acids
Which of the following substances releases hydrogen ions into a solution? acids bases salts glucose
growth hormone-inhibiting hormone (GHIH)
Which of the following will inhibit the secretion of growth hormone? growth hormone-releasing hormone (GHRH) growth hormone-inhibiting hormone (GHIH) somatomedins a posterior pituitary inhibiting hormone
increase aldosterone secretion
Which of the following will the body begin to do in order to compensate for hyperkalemia? vasoconstriction of blood vessels increase ADH secretion increase aldosterone secretion increase the release of atrial natriuretic hormone
increased ADH production
Which of the following would be expected to cause hyponatremia? high intake of sodium increased aldosterone production increased urine output increased ADH production
D. glucose
Which one of the following chemicals is a not an electrolyte?A. calcium phosphate B. potassium chloride C. sodium bicarbonate D. glucose
Endocrine organs are sometimes derived from nervous tissue.
Which one of the following statements about hormones or the endocrine system is correct? -Hormones are distributed only to specific cells having the appropriate membrane receptors. -Endocrine organs are sometimes derived from nervous tissue. -Hormones are secreted onto a surface of the body. -Hormones result in quick, short responses, compared with nervous system responses. -None of the choices is correct.
Insulin triggers the uptake of glucose from the blood.
Which one of the following statements about the endocrine functions of the pancreas is correct? -Alpha cells make insulin. -Insulin triggers the uptake of glucose from the blood. -Diabetes mellitus is caused by a deficiency of glucagon. -Beta cells make glucagon.
All of the above statements are true.
Which one of the following statements is correct? -Many hormones elicit more than one type of response in the body. -Receptors for steroid hormones are located inside target cells. -The series of changes in cellular proteins that convert the extracellular signal to a specific intracellular response is called signal transduction. -Local regulators are signals that link neighboring cells. -All of the above statements are true.
The hypothalamus sends hormones to the anterior pituitary.
Which statement about the lobes of the pituitary is correct? -The anterior pituitary receives hypothalamic hormones from brain cells. -The anterior lobe of the pituitary is nervous tissue that connects directly to the brain. -The posterior lobe of the pituitary is glandular tissue closely associated with the brain. -The hypothalamus sends hormones to the anterior pituitary. -The posterior pituitary produces oxytocin and antidiuretic hormone.
Some toxic materials are actively
secreted into the filtrate
Which of the following primarily involves heat transfer by convection? As you lie on the sand, you can feel the sun's warm rays on your skin. After sunset, you can feel heat from the warm pavement. The water in the lake is so cold that your legs become numb. You roll down the car window to allow the cool breeze to blow through. You sweat profusely as you mow the lawn on a hot summer day.
You roll down the car window to allow the cool breeze to blow through.
glomerulus
a capillary network lying in the glomerular capsule and functioning in filtration
Epinephrine is an example of
a catecholamine.
Helper T cells are part of __
a cell-mediated immune response
In a physiological system operating with positive feedback, _____.
a change in a variable will amplify rather than reverse the change
Aldosterone stimulates ion pumps along the distal convoluted tubule, the collecting tubule, and the collecting duct, causing...
a reduction in the number of sodium ions lost in the urine
A human cell containing 22 autosomes and a Y chromosome is
a sperm
Select the example that most accurately illustrates this statement: "The endocrine and nervous systems act together to regulate an animal's physiology." Select one: a. In response to stress, neurosecretory cells in the adrenal medulla release epinephrine and norepinephrine, which mediate various fight-or-flight responses. b. Signals to the brain stimulate the hypothalamus to secrete a hormone that stimulates or inhibits release of a particular posterior pituitary hormone. The posterior pituitary hormone then acts on a target endocrine tissue to stimulate secretion of another hormone. c. The hypothalamus receives information from hormones throughout the body and brain. In response, it initiates nervous signaling appropriate to environmental conditions.
a. In response to stress, neurosecretory cells in the adrenal medulla release epinephrine and norepinephrine, which mediate various fight-or-flight responses.
Compared to the seawater around them, most marine invertebrates are Select one: a. isoosmotic b. hypoosmotic c. hyperosmotic and isoosmotic d. hyperosmotic. e. hypoosmotic and isoosmotic.
a. isoosmotic
Which of the following would contain blood in a normally functioning nephron? Select one: a. vasa recta b. Bowman's capsule c. loop of Henle d. collecting duct e. proximal tubule
a. vasa recta
A disease that destroys the adrenal cortex should lead to an increase in the plasma levels of
adrenocorticotropic hormone (ACTH).
Which of these is reabsorbed from filtrate?
all of these
To conserve energy, many toads secrete _____ as tadpoles but _____ as terrestrial adults.
ammonia ... urea ( In the water, a tadpole can use the abundant water to release ammonia. But as an adult, with less water available, the toad must use energy to produce urea.)
____ is a highly toxic nitrogenous waste and this waste is typically excreted by ___ and other ___ animals so that it can be readily diluted in the immediate environment.
ammonia, fish and other aquatic
A decrease in the volume of urine excreted would be expected following
an increase in aquaporin channels in collecting duct.
Insect hormones and their receptors
are a focus in pest-control research.
pituitary gland
at the base of the hypothalamus
The glomerular filtration rate is regulated by...
autoregulation, hormonal regulation, autonomic regulation
Growth factors are local regulators that
bind to cell-surface receptors and stimulate growth and development of target cells.
In a positive-feedback system where hormone A alters the amount of protein X Select one: a. it is impossible to predict how A and X affect each other. b. an increase in A always produces an increase in X, which results in an increase in A. c. a decrease in X always causes a decrease in A, which causes an increase in X. d. a decrease in A always produces an increase in X, which results in an increase in A. e. an increase in X always produces a decrease in A, which results in a decrease in X
b. an increase in A always produces an increase in X, which results in an increase in A.
Sexual reproduction Select one: a. guarantees that both parents will provide care for each offspring b. can produce diverse phenotypes that may enhance survival of a population in a changing environment c. allows animals to conserve resources and reproduce only during optimal conditions d. enables males and females to remain isolated while rapidly colonizing habitats e. yields more numerous offspring more rapidly than is possible with asexual reproduction
b. can produce diverse phenotypes that may enhance survival of a population in a changing environment
Sexual reproduction Select one: a. enables males and females to remain isolated while rapidly colonizing habitats b. can produce diverse phenotypes that may enhance survival of a population in a changing environment c. allows animals to conserve resources and reproduce only during optimal conditions d. guarantees that both parents will provide care for each offspring e. yields more numerous offspring more rapidly than is possible with asexual reproduction
b. can produce diverse phenotypes that may enhance survival of a population in a changing environment
These cells are involved in cell-mediated immunity, and they respond to class I MHC molecule-antigen complexes: Select one: a. helper T cells b. cytotoxic T cells c. natural killer cells d. B cells e. macrophages
b. cytotoxic T cells
how is blood pressure/volume detected?
baroreceptors in atria of heart, if volume decreases, baroreceptors activate
If the membrane potential of a neuron decreases, the membrane potential _____.
becomes more positive.
Stimulus (blood glucose levels rise) beta cells of pancreas release insulin
body cells take up more glucose, liver takes up glucose and builds glycogen, blood glucose levels fall; homeostasis; stimulus( blood glucose levels fall) alpha cells of pancreas release glucagon, liver breaks down glycogen and release glucose, blood glucose levels rise
The role of active cytotoxic T cells is to attack ___
body cells that have been infected
The role of cytotoxic T cells is to attack__
body cells that have been infected
immune and lymphatic system functions
body defense; fighting infections and cancer
transport epithelia
both osmoregulation and metabolic waste disposal rely on this; one or more layers of epithelial cells specialized for moving particular solutes in controlled amounts in specific directions; arranged in tubular networks with extensive surface areas; some face outside, while others line channels connected to outside by opening on body surface
An embryonic cell that is "totipotent" is one that can _____.
by itself, give rise to the entire embryo, as cleavage proceeds
A cation that is more abundant as a solute in the cytosol of a neuron than it is in the interstitial fluid outside the neuron is Select one: a. Na+ b. HCO3-. c. K+ d. Ca++ e. Cl-
c. K+
The cerebrospinal fluid is Select one: a. secreted by the hypothalamus b. a secretion of glial cells c. a filtrate of the blood. d. cytosol secreted from ependymal cells. e. a secretion of interneurons.
c. a filtrate of the blood
The cerebrospinal fluid is Select one: a. a secretion of interneurons. b. a secretion of glial cells c. a filtrate of the blood. d. cytosol secreted from ependymal cells. e. secreted by the hypothalamus
c. a filtrate of the blood.
Different body cells can respond differently to the same peptide hormones because Select one: a. each cell converts that hormone to a different metabolite. b. the hormone is chemically altered in different ways as it travels through the circulatory system. c. a target cell's response is determined by the components of its signal transduction pathways. d. different target cells have different sets of genes. e. the circulatory system regulates responses to hormones by routing the hormones to specific targets.
c. a target cell's response is determined by the components of its signal transduction pathways.
The hormone epinephrine causes opposite effects in two populations of target cells because Select one: a. epinephrine crosses the membrane on one set of target cells but binds to membrane-bound receptors in the other set of target cells b. epinephrine can only reach target cells in adipose tissue, as it is fat-soluble c. each set of target cells has different receptor-transduction mechanisms d. the chemical form of epinephrine released by neurons is different from the epinephrine released by endocrine cells e. epinephrine activates biochemical pathways in one set of target cells but works only by changing gene expression in the other set of target cells
c. each set of target cells has different receptor-transduction mechanisms
The suprachiasmatic nuclei are found in the Select one: a. Broca's area. b. epithalamus c. hypothalamus d. amygdala e. thalamus
c. hypothalamus
Which hormone opposes the action of parathyroid hormone?
calcitonin
The body's reaction to PTH (parathyroid hormone), a reduction in plasma levels of calcium, can be opposed by
calcitonin.
The osmolarity of human urine is always exactly equal to plasma osmolarity. is always greater than plasma osmolarity. is always less than plasma osmolarity. can be four times as great as normal osmolarity of human plasma. is determined primarily by the concentration of glucose.
can be four times as great as normal osmolarity of human plasma.
what is the "vasa recta" and what is its function?
capillary network surrounding and running opposite to the renal tubules of nephron. The vasa recta reclaims reabsorbed substances, such as water and sodium ions, from the tubules in medulla
slow effect of aldosterone binding to receptor
causes expression of subunit alpha of ENaC (this channel pumps Na from urine filtrate into principle cell) Na then diffuses across cell and through Na/K channels on other side of principle cell into interstitial fluid
macula densa
cells of the final portion of the ascending limb of the loop of Henle that make contact with the afferent arteriole
flame bulbs
cellular units in a faltworm; cap the branchesof each protonephridium; each has a tuft of cilia; during filtration, the beating of the cilia draws water and solutes from the interstitial fluid through the flame bulb, releasing filtrate into the tubule network
As vertebrates evolved, the increasingly complex structure of the brain conferred increasingly complex function, especially apparent in the _____.
cerebral complex, which is greatly expanded in nonhuman primates and cetacean
Calculation, contemplation, and cognition are human activities associated with increased activity in the
cerebrum
Reabsorption of water continues through
channels formed by aquaporin proteins
connective tissue
cinsists of cells scattered through an extracellular matrix, often consisting of a web of fibers embedded in a liquid, jellylike, or solid foundation
Cytochalasin B is a chemical that disrupts microfilament formation. This chemical would interfere with ____
cleavage
The first stage of embryonic development is _____. This process produces _____.
cleavage ... a cluster of cells
Birds have shorter loops of Henle but
conserve water by excreting uric acid instead of urea
102) How do glucocorticoids enable the body to deal appropriately with stress? A) by stimulating the pancreas to release insulin B) by decreasing the heart rate, thus decreasing blood pressure C) by blocking the neurotransmitters that prepare the body for the stress response D) by increasing blood glucose, fatty acid, and amino acid levels and enhancing blood pressure
d
In the diagram of the uterine cycle above, thickening of the endometrium during the secretory phase is promoted by high levels of which of the following hormones ? Select one: a. Estradiol only b. LH only c. LH and FSH d. Progesterone and Estradiol e. Progesterone only
d. Progesterone and Estradiol
how do changes in blood volume shift the relationship btw plasma osmolality and ADH levels
decrease in blood volume makes the system more sensitive (shifts to left) increase in blood volume = less sensitive (shift to right)
how is pressure detected in juxtaglomerular apparatus
decrease in pressure stimulates deformation of granular cells (epithelial cells in afferent arteriole which bring blood to glomerulus) causing them to secrete renin
The activity of acetylcholine in a synapse is terminated by its
degradation by a hydrolytic enzyme on the postsynaptic membrane
Inadequate ADH secretion results in the inability to reclaim the water entering the filtrate, causing...
dehydration
Two fundamental concepts about the ion channels of a "resting" neuron are that the channels Select one: a. open and close depending on chemical messengers, and are nonspecific as to which ion can traverse them. b. open in response to stimuli, and then close simultaneously, in unison. c. are always open, but the concentration gradients of ions frequently change d. are always closed, but ions move closer to the channels during excitation e. open and close depending on stimuli, and are specific as to which ion can traverse them
e. open and close depending on stimuli, and are specific as to which ion can traverse them
distal convoluted tubule
drains into a collecting duct
Homeostasis typically relies on negative feedback because positive feedback
drives processes to completion rather than to a balance point
Urine is produced by many species in four steps. These steps are : 1. Excretion 2. Reabsorption 3. Secretion 4. Filtration. The correct order of these steps is: Select one: a. 2, 3, 4, 1 b. 3, 4, 2, 1 c. 2, 3, 1, 4, d. 4, 2, 1, 3 e. 4, 2, 3, 1
e. 4, 2, 3, 1
Neurotransmitters can affect postsynaptic cells by Select one: a. initiating signal transduction pathways in the cells. b. causing molecular changes in the cells c. affecting ion-channel proteins d. altering the permeability of the cells. e. All of these options are correct
e. All of these options are correct
A bone marrow transplant may not be appropriate from a given donor (Jane) to a given recipient (Jane's cousin Bob), even though Jane has previously given blood for one of Bob's needed transfusions, because Select one: a. Bob's immune response has been made inadequate before he receives the transplant. b. Jane's class II genes are not expressed in bone marrow. c. a blood type match is less stringent than a match required for transplant because blood is more tolerant of change d. for each gene, there is only one blood allele but many tissue alleles. e. even though Jane's blood type is a match to Bob's, her MHC proteins may not be a match.
e. even though Jane's blood type is a match to Bob's, her MHC proteins may not be a match.
Saltwater fish are strongly hypotonic to their environment. Thus, they tend to: Select one: a. lose both water and salt. b. swim to marine environments for excretion. c. gain both water and salt. d. gain water and lose salts. e. lose water and gain salts
e. lose water and gain salts
Which of the following hormones is needed for the maintenance of a pregnancy and is initially produced by the mother's corpus luteum and subsequently produced by the placenta ? Select one: a. human chorionic gonadotropin b. FSH c. estradiol d. LH e. progesterone
e. progesterone
The amount of filtrate produced in the kidneys each minute is the...
glomerular filtration rate
Which of the following epithelial types is specialized for the regulation of solute movement across membranes? Select one: a. simple epithelium b. squamous epithelium c. columnar epithelium d. excretion epithelium e. transport epithelium
e. transport epithelium
The hormone epinephrine causes opposite effects in two populations of target cells because _____.
each set of target cells has different receptor-transduction mechanisms
The hormone epinephrine causes opposite effects in two populations of target cells because _____.
each set of target cells has different receptor-transduction mechanisms; Look at the epinephrine example in your text. That hormone can trigger different responses in different target cells. Epinephrine can trigger vasodilation responses (blood vessels in skeletal muscles used for fight-or-flight) and vasoconstriction responses (gut vasculature) in an emergency that evokes its secretion.
The steroid hormone that coordinates molting in arthropods is
ecdysone.
Which embryonic tissue is responsible for forming the membrane that can be found completely surrounding the embryo while in utero?
ectoderm
urethra
empties urine to the outside near the vagina or through the penis; sphincters near the junction regulate urination
Urea and NaCl form the osmotic gradient that
enables the kidney to produce urine that is hyper osmotic to the blood
animal tissue types
epithelial, nervous, connective, muscle
The movement of substances out of the glomerulus and into Bowman's capsule is referred to as
filtration
The three processes involved in urine formation are...
filtration, reabsorption, and secretion
duodenum
first part of small intestine
Excretory structures known as protonephridia are present in
flatworms
Angiosperms are different from all other plants because only they have _____.
flowers
stimulus
fluctuations in the variable above or below the set point
Endocrine signaling regulates
homeostasis, development, and behavior
ADH secretion is regulated by what signal?
increase in osmolality (amt of solutes in ECF)
If ATP production in a human kidney was suddenly halted, urine production would decrease, and the urine would be isoosmotic compared to plasma. increase, and the urine would be hyperosmotic compared to plasma. decrease, and the urine would be hypoosmotic compared to plasma. increase, and the urine would be isoosmotic compared to plasma. come to a complete halt.
increase, and the urine would be isoosmotic compared to plasma.
angiotensin II
increases reabsorption of Na+, other solutes and water, which increases blood volume
During periods of strenuous exercise, blood flow...
increases to skin and skeletal muscles; decreases to kidneys
atrial natriuretic peptide
inhibits Na+ and H2O reabsorption in the proximal convoluted tubules and collecting ducts
renal medulla
inner part of the kidney; supplied with blood by a renal artery and drained by a renal vein; tightly packed excretory tubules and associated blood vessels lie in here
The appropriate group of animals to examine to observe a Malpighian tubule would be _____.
insects and other terrestrial arthropods
uric acid
insects, land snails, many reptiles, including birds, excrete this as primary nitorgenous waste; relatively nontoxic and does not readily dissolve in water; it can be excreted as a semisolid paste with very little water loss; more energetically expensive
Molecules are transported actively and passively from the filtrate into the
interstitial fluid and then capillaries
An antigen _
is a foreign molecule that evokes a specific response by a lymphocyte
A chemical signal operating in a paracrine manner is one that
is active at a neuronal synapse.
Posterior pituitary
is an extension of the hypothalamus, releases oxytocin
how does pregnancy shift the relationship btw plasma osmolality and ADH levels
it causes ADH levels to rise more quickly in response to lower osmolality levels (shifts curve to the left-more sensitive)---pregnant women retain more water
If a person loses a large amount of water in a short period of time, he or she may die from dehydration. ADH can help reduce water loss through its interaction with its target cells in the
kidney
excretory system components
kidneys, ureters, urinary bladder, urethra
Incontinence
lack of voluntary control of micturition
Most bryophytes, such as mosses, differ from all other plants in that they _____.
lack true leaves and roots
In some organisms such as certain fungi and algae, cells undergo the cell cycle repeatedly without subsequently undergoing cytokinesis. What would result from this?
large cells containing many nuclei
muscular system functions
locomotion and other movement
Mammals in dry environment have
long loops of Henle
Juxtamedullary nephrons can concentrate salt effectively in the renal medulla because of their long
loops of Henle.
what signals increase firing of baroreceptors and what do they act on?
low blood pressure/volume causes receptors to fire on vasomotor centers in the medulla which relay signal to hypothalamus to release ADH
angiotensin II
low blood volume or low blood pressure stimulate renin-induced production of this hormone
an obstruction in the afferent arteriole would result in?
lower rate of GFR, decrease pressure in glomerular capillaries
insulin
lowers blood glucose level
respiratory system components
lungs, trachea, other breathing tubes
A rapid increase in the _____ level stimulates ovulation. A rapid increase in the _____ level stimulates ovulation.
luteinizing hormone
What hormone stimulates hormone production by the ovaries and testes?
luteinizing hormone (LH)
Which hormone stimulates hormone production by the ovaries and testes?
luteinizing hormone (LH)
Which hormone stimulates hormone production by the ovaries and testes?
luteinizing hormone (LH) ( LH stimulates hormone production by both the ovaries and testes.)
The anterior and posterior lobes of the pituitary differ in that _____.
many anterior pituitary hormones regulate other endocrine glands whereas posterior pituitary hormones regulate nonendocrine tissues
Organisms categorized as osmoconformers are most likely
marine
Organisms categorized as osmoconformers are most likely
marine.
As the filtrate passes through the proximal tubule
materials to be excreted become concentrated
Osmoregulation and excretion are _____. mechanisms that require continual water loss mechanisms that maintain volume and composition of body fluids chemical processes that completely stop during torpor and hibernation ways that animals control their external environment mechanisms for the homeostatic control of body temperature
mechanisms that maintain volume and composition of body fluids
Osmoregulation and excretion are _____.
mechanisms that moderate change in interstitial fluid ( They are both crucial to maintaining homeostasis.)
Increases and decreases of the heart rate result from changes in the activity of the
medulla oblongata.
The unconscious control of respiration and circulation is associated with the
medulla oblongata.
Genetic variation occurs when chromosomes are shuffled in fertilization and what other process?.
meiosis
omologous chromosomes move toward opposite poles of a dividing cell during
meiosis I.
Winter hibernation and spring reproduction in bears are cued by seasonal changes in the secretion of
melatonin from the pineal gland.
aquaporins
membrane proteins that function as water channels
In an experiment, rats' ovaries were removed immediately after impregnation and then the rats were divided into two groups. Treatments and results are summarized in the table. The results most likely occurred because progesterone exerts an effect on the
metabolism of the uterus.
When antidiuretic hormone levels rise, the DCT becomes...
more permeable to water, water reabsorption increases
As filtrate moves down the loop of Henle, the surrounding interstitial fluid becomes _____ concentrated than the filtrate, so _____ leaves the filtrate.
more....water.
For hormones that homeostatically regulate cellular functions,
negative feedback typically regulates hormone secretion.
How do nonsteroid hormones differ from steroid hormones?
nonsteroid hormones act via signal transduction pathways; steroid hormones do not act via signal transduction pathways
glial cells
nourish, insulate, replenish neurons and in some cases moderate neuron function
Dolphins can be awake and asleep at the same time because _____.
one side of the brain can sleep while the other side maintains swimming and breathing behaviors
The reason that the steroid hormone aldosterone affects only a small number of cells in the body is that
only its target cells contain aldosterone receptors.
Other reptiles have
only optical nephrons but also excrete nitrogenous waste as uric acid
Hormones are transported throughout the circulatory system, but they affect only specific tissues or cells because
only the target cells have receptors for the hormone
Hormones are transported throughout the circulatory system, but they affect only specific tissues or cells because
only the target cells have receptors for the hormone.
In humans, oogenesis in comparison to spermatogenesis is different in that _____
oogenesis does not complete meiosis until after fertilization, but spermatogenesis is complete before the sperm leave the body
Two fundamental concepts about the ion channels of a "resting" neuron are that the channels
open and close depending on stimuli, and are specific as to which ion can traverse them.
Atrial natriuretic peptide (ANP)
opposes the RAAS; ANP is released in response to an increase in blood volume and pressure and inhibits the release of renin
renal cortex
outer part of the kidney; supplied with blood by a renal artery and drained by a renal vein; tightly packed excretory tubules and associated blood vessels lie in here
reproductive system components
ovaries or testes and associated organs
Which of the following structures in females is analogous in function to the vas deferens in males?
oviduct
The anatomical location for the typical union of a sperm and an egg (conception) is the ___
oviducts
A pregnant woman comes into the hospital past her due date. The doctor decides it is time for the baby to be delivered. Before performing a cesarean section, the doctor wants to try to induce labor. Which of the following would she most likely inject?
oxytocin
ADH synthesis and secretion is analogous to what other hormone
oxytocin (both from magnocellular cells to posterior pituitary)
Linkage to membrane-bound receptor proteins on target cells activates the typical actions of the
pancreatic hormones.
A cluster of tumor cells that produces and secretes growth factors to induce surrounding cells to grow and divide are showing which type of cell-to-cell signaling?
paracrine
On a submarine expedition to the ocean bottom, you discover a population of fish that uses a method of reproduction in which female offspring develop from unfertilized eggs. What type of reproduction is this?
parthenogenesis
What term describes the mode of asexual reproduction in which offspring develop from unfertilized eggs?
parthenogenesis
what is the "renal fraction"?
percentage of cardiac output (of blood) that flows through the kidney; = 21% average
Antidiuretic hormone (ADH) increases the
permeability of the collecting duct epithelium to water; water osmolarity increases, this triggers the release of ADH, which helps to conserve water
The "selectivity" of a particular ion channel refers to its
permitting passage only to a specific ion.
Unlike most angiosperms, grasses are pollinated by wind. As a consequence, some unnecessary parts of grass flowers have almost disappeared. Which of the following parts would you expect to be most reduced in a grass flower?
petals
Suppose that substance X is secreted by one cell, travels via interstitial fluid to a neighboring cell, and produces an effect on that cell. All of the following terms could describe this substance except
pheromone.
What is the only type of chemical signal that is not intended to alter the physiology of the animal producing that signal?
pheromones
The filtrate in the proximal convoluted tubule of the human does not normally include dissolved gasses. glucose. plasma proteins. amino acids. ions.
plasma proteins.
The adaptation that made possible the colonization of dry land environments by seed plants is most likely the result of the evolution of _____.
pollen
Water-soluble hormones
polypeptides and amines; do not pass through cell membranes
Three major classes of molecules function as hormones in vertebrates
polypeptides, amines derived from amino acids, steroid hormones
condition resulting in excessive volume of urination?
polyuria
fenestrations
pores in the glomerular endothelial cells that allow filtration of blood solutes but not blood cells and platelets
Endocrine structures derived from nervous tissue include the
posterior pituitary gland and the adrenal medulla.
thermoregulation
process by which animals maintain an internal temperature within a normal range
excretion
process that rids the body of nitrogenous metabolites and other metabolic waste products
The gonads, testes and ovaries
produce most of the sex hormones: androgens, estrogens, and progestins
effect of juxtaglomerular apparatus
produce renin which converts angiotensinogen produced by liver to angiotensin 1
Hyperosmotic urine can be
produced only using energy to transport solutes against concentration gradients
Which of the following is not a normal response to increased blood osmolarity in humans?
production of more dilute urine
Which hormone stimulates milk production?
prolactin
Which hormone stimulates milk production?
prolactin ( Prolactin, secreted by the anterior pituitary, stimulates milk production by the mammary glands.)
In a lactating mammal, the two hormones that promote milk synthesis and milk release, respectively, are
prolactin and oxytocin.
Pros and Cons of Urea
pros: less toxic, requires less water cons: energetically expensive
Based on their effects, which pair below would not be expected to be active at the same time and place?
prostaglandin F and nitric oxide
integumentary system functions
protection against mechanical injury, infection, dehydration; thermoregulation
cartilage
provides flexible support in the spine and elsewhere
In a nephron, the long tubular passageway through which the filtrate passes includes...
proximal and distal convoluted tubules and loop of Henle
Approximately 60-70 percent of the water is reabsorbed in the...
proximal convoluted tubule
The route of filtrate flow in correct order from its origin to teter
proximal convoluted tubule - descending limb of loop of Henle - ascending limb o f loop of Henle - distal convoluted tubule - collecting duct - papillary duct - minor calyx - major calyx - renal pelvis
an obstruction in the efferent arteriole would result in?
raise pressure in glomerular capillaries
Angiotensin 2
raises blood pressure and decreases blood flow to the kidneys; stimulates the release of the hormone aldosterone, which increases blood volume and pressure
cortical nephrons
reach only a short distance into the medulla; most of the nephrons are these
Unlike an earthworm's metanephridia, a mammalian nephron is intimately associated with a capillary network. functions in both osmoregulation and excretion. forms urine by changing fluid composition inside a tubule. receives filtrate from blood instead of coelomic fluid. has a transport epithelium.
receives filtrate from blood instead of coelomic fluid.
collecting duct
receives processed filtrate from many nephrons and transports it to the renal pelvis
sensor
receptor
The fact that there are about a million different antigen receptors possible in human B cells is based on __
recombination of the segments of the receptor DNA that make up the functional receptor genes of differentiated B cells
reabsorpotion
recovers useful molecules and water from the filtrate and returns them to the body fluids; valuable solutes like glucose, certain salts, vitamins, hormones, and amino acids, are reabsorbed by active transport
A nerve poison that blocks acetylcholine receptors on dendrites would _____.
reduce the binding of acetylcholine to its receptors on the postsynpatic membrane. The binding of neurotransmitter molecules to their specific receptors on the postsynaptic membrane opens ion channels, which completes the transmission of the impulse to the receiving cell. A nerve poison that blocked the acetylcholine receptors would prevent reception of the signal.
A countercurrent heat exchanger enables an animal to _____.
reduce the loss of body heat to the environment
Birds, insects, and many reptiles excrete nitrogenous waste in the form of uric acid, which
reduces water loss compared to other nitrogenous wastes, but requires more metabolic energy to produce
Immediately after an action potential passes along an axon, it is not possible to generate a second action potential; thus, we state that the membrane is briefly
refractory
In a neuron, during the depolarization phase that may trigger an action potential _____.
some voltage-gated sodium channels are open
positive feedback
reinforces a stimulus, leading to an even greater response; circulating oxytocin, stimulating contractions during birth
Uric acid is
relatively nontoxic and does not dissolve readily in water
Increased activity in the sympathetic nervous system leads to Select one: a. relaxation of the airways in the lungs b. increased secretion by the gallbladder c. increased secretion by the pancreas. d. increased contraction of the stomach e. decreased heart rate.
relaxation of the airways in the lungs
Which of the following is a characteristic of the early stages of local inflammation?
release of histamine
The anterior pituitary makes and
releases hormones under regulation of the hypothalamus
The counter-regulatory functions of the pancreas refer to the fact that it _____.
releases one hormone that reduces glucose levels in the blood and another that increases them; The counter-regulatory hormones and their actions are insulin, which decreases glucose levels in the blood, and glucagon, which increases glucose levels in the blood.
A benign tumor, but not a malignant tumor, is one in which the cancerous cells ____
remain confined to their original site
The____are the major blood vessels transporting blood to the kidneys
renal arteries
Which regions of the nephron function independently of hormonal control for the most part?
renal corpuscle, proximal tubule, and loop of Henle
Urine formed by a kidney collects in the _____ before being drained from the kidney by the _____ and transported to the _____.
renal pelvis ... ureter ...urinary bladder
The substances that influence the GFR by regulating blood pressure and volume are...
renin, erythropoietin, ADH
Osmoregulatory mechanisms of freshwater fish include
salt uptake in gills and water excretion in urine
malpighian tubules
screte certain solutes and wastes into the lumen of the tubule; the filtrate passes through the digestive tract and water absorption by osmosis follows; in insects and terrestrial arthropods
The movement of substances from the blood into the proximal tubule is known as
secretion
The movement of substances from the blood into the proximal tubule is known as _____.
secretion
The osmoregulatory process called secretion refers to the
selective elimination of excess ions and toxins from body fluids.
Materials are returned to the blood from the filtrate by which of the following processes?
selective reabsorption
hypothalamus
sensors for thermoregulation here; group of nerve cells functions as a themrostat; releasing and inhibiting hormones; regulates anterior pituitary
endocrine system
signaling molecules released into the bloodstream by endocrine cells are carried to all location in the body
Neuroendocrine
signals are the chemical messengers called neurotransmitters. They diffuse into the tiny gap between neurons and are not discussed here. Neuroendocrine signals are also hormones.
autocrine
singal act on the same cells that release them
ureter
urine produced by each kidney exits through this duct
muscular system components
skeletal muscles
muscle tissue
skeletal, smooth, cardiac; contain actin and myosin for contraction
skeletal system components
skeleton; bones, tendons, ligaments, cartilage
what two solutes draw water out of collecting duct?
sodium & chloride
Which of these is reabsorbed from filtrate?
sodium chloride glucose water amino acids bicarbonate ions
What is reabsorbed from filtrate?
sodium chloride, glucose, water and amino acids
Increased anitdiuretic hormone (ADH) secretion is likely after___.
sweating-induced dehydration increases plasma osmolarity
When several IPSPs arrive at the axon hillock rapidly in sequence from a single dendritic location, hyperpolarizing the postsynaptic cell more and more and thus preventing an action potential, this is an example of
temporal summation.
In human embryonic development, which of the following pairs of hormones are released by the developing testes and result in development of the male reproductive tract and inhibition of the female reproductive tract?
testosterone and Mullerian inhibitory substance
Which of the following is similar in structure to cholesterol?
testosterone, estradiol, and cortisol
The force driving simple diffusion is___, while the energy source for active transport is ___.
the concentration gradient; ATP
What is crossing over?
the exchange of homologous portions of nonsister chromatids
Thyroid hormones exert negative feedback effects at all levels of the hypothalamic-pituitary-thyroid gland axis, so we should expect to find thyroid hormone receptors at
the hypothalamus, the anterior pituitary gland, and the targets of thyroid hormones throughout the body
Mammals and most adult amphibians convert ammonia to
the less toxic urea; produced in the liver and carried to the kidneys
Endocrine pathways are subject to regulation by
the nervous system, including the brain
In sperm competition, what is "second-male advantage"?
the observation that when females mate with two males, the second male fertilizes most of the eggs
Where in the female reproductive tract does fertilization occur ?
the oviduct
Which of the following has both endocrine and exocrine activity?
the pancreas
Melatonin is secreted by
the pineal gland during the night.
Urea is
the primary nitrogenous waste product of humans.
Oogenesis
the process of forming eggs
podocytes
the visceral layer of the glomerular capsule consisting of modified simple squamous epithelial cells
It is difficult to observe individual chromosomes with a light microscope during interphase because ___
they have uncoiled to form long, thin strands
Cell-mediated immunity differs from humoral immunity in that __
they respond differently to invaders
The primary reason steroid hormones usually act slowly is that _____.
they turn genes on or off and it takes time for gene products to build up or become depleted
Select the choice that describes neurons with the fastest conduction velocity for action potentials.
thick, myelinated neurons
The collecting duct conducts filtrate
through the osmolarity gradient, and more water exits the filtrate by osmosis
Which of these glands lies closest to the throat region?
thyroid
Iodine is added to table salt to help prevent deficiencies of an essential mineral needed for the proper function of the
thyroid glands.
osmoconformer
to be isoosmotic with its surroundings; all are marine animals; way to maintain water balance
Hypothyroidism
too little thyroid function, can produce symptoms such as weight gain, lethargy, cold intolerance
Which of these is the second of the three stages of cell signaling?
transduction
countercurrent exchange
transfer of heat or solutes between fluids that are flowing in opposite directions
True of false? The pancreas is responsible for producing hormones that maintain the homeostatic levels of glucose in the blood.
true
Water balance is affected by
type of wastes, quantity of waste products
The most abundant solute in urine is
urea (and other nitrogenous wastes)
Select the pair in which the nitrogenous waste is incorrectly matched with the benefit of its excretion.
urea-very insoluble in water
Most excretory systems produce
urine by refining a filtrate derived from body fluids
As a result of the non-selectivity of the kidney's filtration of small molecules
useful substances must be selectively reabsorbed
The kidney's filtration process is nonselective; therefore, _____.
useful substances must be selectively reabsorbed
regulator
uses internal mechanisms to control internal change in the face of external fluctuation; otters
ammonia
very toxic, in part because its ion interferes with oxidative phosphorylation; many species expend energy to convert it to a less toxic compound, either urea or uric acid, prior to excretion
how is decreased volume and Na detected?
via juxtaglomerular apparatus
ADH is involved in regulating excretion of [...] Aldosterone is involved in excretion of [...]
water through aquaporins Na in the kidney
The descending loop of Henle is permeable to ____ presence of _____
water, but not salt ,aquaporin channels
osmoregulator
way to maintain water balance; control internal osmolarity independent of environment; enables animals to live in environments that are uninhabitable for osmoconformers, such as freshwater and terrestrial habitats
Which of the following would increase the rate of heat exchange between an animal and its environment? vasoconstriction feathers or fur blubber or fat layer wind blowing across the body surface countercurrent heat exchanger
wind blowing across the body surface