Basic Physio Q's I Get Wrong
The volume of blood ejected from the ventricle with each contraction can be described by the equation ________.
(end-diastolic volume) - (end-systolic volume)
Which of the following best represents the endocochlear potential?
+80 mV
Glyceraldehyde-3-phosphate dehydrogenase
- produces NADH which can feed into electron transport chain
how many neurons are in the brain
100 billion
Adequate treatment of diabetes includes maintaining fasting blood glucose levels below what value?
115 mg/dl
At rest, ________ percent of the blood pumped by the heart goes to the central nervous system as the central nervous system utilizes ________ percent of the oxygen consumed by the body.
15%, 20%
The first step of the Na+/K+ pumpʹs activity involves the binding of which of the following?
3 Na+ to their binding site on the inside of the cell. Na+ binding precedes K+ binding.
Provide the correct number in each blank. For each acetyl CoA that enters the Krebs cycle, ________ NAD(s) are reduced, ________ FAD(s) are reduced, and ________ ATP are synthesized by substrate-level phosphorylation.
3, 1, 1
What percentage of adults in the US are obese
30%
What percentage of people with diabetes develop peripheral neuropathy
30%
What percentage of people with neuropathy have it secondary to diabetes?
30%
The cap goes on the ______, and the poly A tail goes on the _______.
5', 3'
With the 38 moles of ATP that are generated within a cell from 1 mole of glucose, what percentage of the energy released from glucose is lost as heat?
60%
The complete oxidation of glucose releases how many kcal of energy for every mole of glucose?
686
How much energy is required to produce 1 mole of ATP?
7 kcal
What percentage of people in the US have diabetes?
9%
With a systolic pressure of 135 mm Hg and a diastolic pressure of 75 mm Hg, mean arterial pressure would be ________.
95 mm Hg
What is the normal fasting blood glucose level?
<100 mg/dl
Normal blood glucose level
<140 mg/dl
What is phosphatidylinositol-4,5-biphosphate?
B) a phospholipid in plasma membranes
Which of the following adaptations does NOT generally occur with aerobic exercise? A) an increase in the number of mitochondria per muscle fiber B) an increase in the number of myofibrils per muscle fiber C) a conversion of fast glycolytic fibers to fast oxidative fibers D) an increase in the blood supply to the muscles E) an increase in the aerobic capacity of muscle
B) an increase in the number of myofibrils per muscle fiber
The most acute allergic response is anaphylactic shock, which can be deadly due to the histamine-induced ________. A) increase in peripheral resistance that decreases cardiac output B) decrease in peripheral resistance that decreases mean arterial pressure C) decrease in peripheral resistance that increases cardiac output D) increase in capillary permeability E) local decrease in resistance with little effect on mean arterial pressure
B) decrease in peripheral resistance that decreases mean arterial pressure
What are different recognition sites on the same antigen called? A) alleles B) epitopes C) antigen receptors D) variable regions E) perforins
B) epitopes
Which of the following chemical messengers is NOT derived from an amino acid? A) epinephrine B) testosterone C) histamine D) thyroid hormones E) serotonin
B) testosterone
Each antibody can bind ________. A) two different types of epitopes B) two epitopes of the same kind C) three epitopes of the same kind D) two epitopes of one kind and one epitope of a different kind E) one epitope only
B) two epitopes of the same kind
Antibodies are classified not only by their function, but by the ________. A) variable region B) type of heavy chain C) type of light chain D) number of disulfide bonds E) number of light chains
B) type of heavy chain
In order to mount a response, particular B or T cells must express the appropriate ________ that will bind to the ________. A) antigen : antigen receptor B) epitope : antigen C) antigen receptor : antigen D) antigenic determinant : antigen E) antigen : antibody
C) antigen receptor: antigen
Which of the following is NOT an adverse effect of glycosylation caused by hyperglycemia? A) delayed wound healing B) increased capillary permeability lipolysis C) beta cell degeneration D) oxidative stress E) atherosclerosis
C) beta cell degeneration
The lifespan of plasma cells is approximately several ________. A) minutes B) hours C) days D) weeks E) months
C) days
In humans, the major histocompatibility (MHC) molecule is known as the ________. A) human leukocyte association B) human lymphoid antibody C) human leukocyte antigen D) human leukocyte antibody E) human lymphoid tissue
C) human leukocyte antigen
Which of the following statements about end-plate potentials is FALSE? A) They are graded potentials. B) They are always depolarizations. C) They are always of sufficient magnitude to generate an action potential in the sarcolemma. D) They are a result of acetylcholine binding to muscarinic cholinergic receptors. E) They are terminated by removal of acetylcholine from the synaptic cleft.
D) They are a result of acetylcholine binding to muscarinic cholinergic receptors.
What type of phagocytic cell has long processes?
Dendritic cells
What is the most common inhibitory neurotransmitter in the central nervous system?
GABA
IPSPs are produced when GABA binds to what class of receptor?
GABA A
Which GABA receptor is coupled to chloride channels?
GABA A
Peyer s patches are peripheral lymphoid tissue located where?
GI tract wall
Hexokinase v.s. Glucokinase
Hexokinase: present in most tissues, low Km (reaches max velocity at low glucose), inhibited by G-6-P Glucokinase: present in hepatocytes and pancreatic B-islet cells (along with GLUT 2, acts as the glucose sensor), high Km (acts on glucose proportionally to its concentration), induced by insulin in hepatocytes
Which of the following best describes ON-center, OFF-surround cells in the retina?
They are ganglion cells that are excited by light applied in the center of their visual fields and inhibited by light in the surrounding regions of their visual fields.
What is the function of T tubules?
They conduct action potentials from the sarcolemma to the interior of the muscle cell.
What do cofactors do?
They must be present in order for the enzyme to bind to the substrate
What is the role of ryanodine receptors in cardiac muscle?
They release calcium from the sarcoplasmic reticulum.
T/F The dorsal column-medial lemniscal pathway carries mechanoreceptive and proprioceptive information to the thalamus, whereas the spinothalamic tract carries thermoreceptive and nociceptive information.
True
T/F The eighth cranial nerve carries information about hearing and equilibrium from the ear to the central nervous system.
True
T/F The heavy chains of an antibody comprise portions of both the constant and variable regions of the antibody.
True
T/F The most abundant neurotransmitter in the peripheral nervous system is acetylcholine.
True
T/F The parasympathetic nervous system exerts more discrete effects on effector organs than the sympathetic nervous system due to the independence of parasympathetic ganglia.
True
T/F The photoreceptors responsible for resetting the light/dark cycle contains a photopigment called melanopsin.
True
T/F The preganglionic neurons of the sympathetic nervous system originate in the spinal cord from a region of gray matter called the intermediolateral cell column.
True
T/F The primary source of calcium that drives skeletal muscle contraction is the sarcoplasmic reticulum.
True
T/F The process of phagocytosis takes less than a tenth of a second.
True
T/F The velocity of shortening during an isometric contraction is zero.
True
T/F The velocity of shortening of a muscle is greatest when there is no load on the muscle.
True
T/F The vestibular apparatus can only detect changes in the rate of head movement.
True
T/F There are no slow glycolytic fibers
True
T/F There are separate receptors for warm and cold.
True
T/F There is no summation of cardiac muscle.
True
T/F Transcutaneous nerve stimulation describes a technique whereby current applied to the skin stimulates large diameter afferent axons (A fiber) to inhibit the transmission of a painful stimulus from the C fiber to a second-order neuron.
True
T/F We generally do NOT perceive information transmitted by visceral afferents.
True
T/F diabetic nephropathy is accompanied by an increase in glomerular filtration
True
T/F diabetic retinopathy is the leading cause of blindness in adults
True
What type of channels that are present within the varicosities of autonomic neurons are absent from the axon terminal of other neurons?
Voltage-gated Na+ and K+ channels
What branch of the nervous system is considered the involuntary nervous system?
autonomic nervous system
do plasma cells develop into b cells or do b cells develop into plasma cells
b cells develop into plasma cells
Which of the following cells is the precursor cell for the olfactory cells?
basal cells
The organ of Corti is located on what membrane?
basilar membrane
Certain epithelial cells have a decided polarity where the ________ membrane faces the lumen of a hollow tube, whereas the ________ membrane faces the extracellular fluid.
basolateral
When awake and alert, the brain is generating ________ waves that are detectable with an electroencephalogram.
beta
What class of adrenergic receptor activates the enzyme adenylate cyclase?
beta1, beta2, and beta3
Adrenergic receptors with the greatest affinity for epinephrine are ________ receptors.
beta2
The activation of helper T cells involves two simultaneous events: ________ and ________.
binding to cells with the class II major histocompatibility (MHC) molecule, the secretion of interleukin-1 by those cells, which stimulates proliferation and differentiation of helper T cells
Hyperglycemia (Type 1, Type 2, both, or neither)
both
Polyuria
both
the zona fasiculata secretes
both androgens and glucocorticoids
Which of the following hormones regulates plasma calcium levels?
both calcitonin and parathyroid hormone
Cilia
composed of 10 microtubules connected by the protein dynein that generate the force necessary to cause the microtubules to slide past one another, thereby moving the cilia.
_______ is associated with high visual acuity.
cones
The transitioning of a memory from short to long term is called ________.
consolidation
Which of the following is true of ALL muscle types?
contract by using the sliding filament mechanism and cross-bridge cycling
Activation of the sympathetic nervous system causes (contraction/relaxation) of the (circular/radial) muscle, which causes pupillary (constriction/dilation).
contraction : radial : dilation
A (concave/convex) lens causes light waves to converge onto a focal point.
convex
37) The cornea and lens are ________ surfaces that cause light to converge on a ________.
convex, focal point
Light waves refract as they pass through what structures of the eye?
cornea and lens
Blood supply to the heart comes from
coronary arteries
Progesterone is a precursor for the synthesis of
cortisol
adrenal cortex hormones
cortisol, DHEA, aldosterone, androgens, estrogen
Parasympathetic preganglionic neurons travel in what nerves?
cranial and pelvic nerves
Which of the following is an INCORRECT match between cranial nerve and special sense?
cranial nerve III - taste
The parasympathetic nervous system is also called the ________ division of the autonomic nervous system.
craniosacral
What enzyme catalyzes the reaction that creates creatine phosphate?
creatine kinase
The bone overlying the olfactory epithelium is called the ________.
cribiform plate
Axons of the olfactory nerve travel through what special structure?
cribriform plate
The repeated, oscillating interaction between actin and myosin that results in the generation of force by a skeletal muscle cell is called what?
cross-bridge cycling
The stereocilia and kinocilium on the hair cells of the ampulla project into what structure?
cupula
What enzyme catalyzes synthesis of prostaglandins from arachidonic acid?
cyclooxygenase
____________ catalyzes synthesis of prostaglandins and thromboxanes.
cyclooxygenase
Biogenic amines are synthesized in what region of a neuron?
cytosol of the axon terminal NOT the axon hillock
________ kill cells infected by a ________ as part of the specific immune response.
cytotoxic T cells, virus
Before converting amino acids into intermediates for energy metabolism, they must first undergo
deamination
In diabetes mellitus type 2, blood vessel damage occurs primarily through what process?
decrease in nitric oxide release from endothelial cells
When leukocytes release the contents of their cytoplasmic granules, the process is called ________.
degranulation
Bending of stereocilia of a hair cell toward the kinocilium causes (depolarization/hyperpolarization) of the hair cell.
depolarization
Tight junctions between capillary endothelial cells in the central nervous system create the blood-brain barrier, thereby restricting what type of movement of molecules into the brain?
diffusion of hydrophilic
Which of the following is the voltage sensor that initiates an increase in cytoplasmic calcium in response to an action potential?
dihydropyridine receptor
The radial muscles of the iris are innervated by the ________ nervous system and their contraction causes pupillary ________.
dilation
During intense (heavy) exercise, the ability of oxidative phosphorylation to provide enough ATP for force generation by the skeletal muscle is ________, thereby causing the muscle fiber to derive energy from ________.
diminished, substrate-level phosphorylation
pyramidal tract
direct pathway from the motor cortex to the spinal cord. The axons terminate in the ventral horn and are called the upper motor neurons. Some synapse directly on the motor neurons, while others synapse with interneurons. Most of the axons in the pyramidal tract cross over in the medulla. The pyramidal tract controls fine, discrete movements of the distal extremities.
The only non-peptide/protein tropic hormone is ____________.
dopamine
Where are the cell bodies of afferent neurons located?
dorsal root ganglia
The protein ________ is responsible for generating force as microtubular proteins slide past one another.
dynein
Which of the following does NOT have nicotinic cholinergic receptors?
effector organs for the parasympathetic nervous system
Is the lateral horn afferent or efferent
efferent
The fluid inside the semicircular canals is (endolymph / perilymph).
endolymph
Which of the following physiological responses are associated with an elevation in parasympathetic nervous system activity?
enhanced absorption of nutrients
In addition to functioning as a transporter, primary active transporters also function as ________ in order to make use of energy.
enzymes
adrenal medulla hormones
epinephrine, norepinephrine
Which of the following is NOT part of the explanation for the all-or-nothing property of an isometric twitch contraction of skeletal muscle?
equivalent activation of calmodulin stimulating myosin light-chain kinase activity
Name the two hormones released in females in response to LH.
estrogens and progesterones
Connects the middle ear to the pharynx.
eustachian tube
When an action potential is generated within a motor neuron, ________.
every muscle cell of the motor unit is stimulated to contract
A skeletal muscle is composed of a number of ________, each composed of many muscle fibers bundled by connective tissue.
fascicles
High shortening velocities.
fast twitch muscle
The decreased ability of a muscle to maintain a constant force of contraction during repetitive stimulation is called what?
fatigue
These cells secrete collagen and aremost active during the remodeling phase of wound healing.
fibroblasts
What cell type lays down new extracellular matrix and collagen to form scar tissue?
fibroblasts
What cell type lays down the new extracellular matrix as a wound heals?
fibroblasts
What cell type produces proteoglycans and glycosaminoglycans?
fibroblasts
When the ciliary muscles are relaxed, the lens is relatively ________, allowing the eye to focus on objects that are ________.
flat, distant
What is the first component of the electron transport chain that accepts electrons from an NADH molecule?
flavin mononucleotide
List the three mechanisms whereby force of individual skeletal muscle fibers can be altered.
frequency of stimulation (summation), fiber diameter (sarcomeres in parallel), and fiber length
Which cerebral lobe contains the primary motor cortex?
frontal lobe
What type of efferent neuron innervates intrafusal muscle fibers?
gamma motor neurons
The first neurons capable of generating action potentials in the transmission pathway for visual information detected by rods and cones are the ________ cells.
ganglion cells
What structure provides the pathway for the movement of electrical current between the cells of the conduction pathway and the ventricular myocytes?
gap junctions
Intercalated disks contain what type of special junctions?
gap junctions and tight junctions
The term autorhythmicity refers to the heart s ability to ________.
generate its own contractile cycle
7) What is another name for a receptor potential produced at sensory receptors?
generator potential
An increase in pressure within the eye due to expansion of the aqueous humor that can eventually compromise blood flow to the eye is called ________
glaucoma
Cellobiose
glucose + glucose
sucrose is composed of
glucose and fructose
maltose is composed of
glucose and glucose
Most energy comes from substrate-level phosphorylation.
glycolytic
White muscle.
glycolytic
Fatigue rapidly.
glycolytic muscle
main hormones transported by the hypophyseal portal system
gonadotropin-releasing hormone, corticotropin-releasing hormone, growth hormone-releasing hormone, and thyrotropin-releasing hormone.
Are axon terminals considered part of white matter or gray matter
gray matter
During summation, calcium release is (greater than / less than / equal to) calcium reuptake.
greater than
An enzyme-linked receptor called ________ catalyzes the conversion of GTP to cGMP
guanylate cyclase
The detection of sweet by taste receptors occurs via the binding of organic molecules to receptors on the cell membrane activating ________ that ultimately causes a ________.
gustducin, potassium channel closes
Both the auditory and vestibular systems rely upon ________ to detect movement of fluid within the ear.
hair cells
_________________ secrete interleukin-2 to facilitate B cell proliferation into memory B cells in addition to effector cells.
helper t cells
Glycosylation of what protein is used as a marker for measuring blood glucose levels ?
hemoglobin
While ________ is released early in the inflammatory response to inhibit blood clotting, the ________ that have leaked into the interstitial space become active and isolate the region of damage.
heparin, clotting factors
Which of the following enzymes has a greater affinity for glucose: aldose reductase or hexokinase?
hexokinase
parathyroid hormone
hormone of the parathyroid glands; increases blood calcium and phosphate levels
Thymosin
hormone of the thymus, stimulates the maturation of lymphocytes into T cells of the immune system
What is the portion of a gene that is capable of being bound by a particular hormone-receptor complex to stimulate alterations in that geneʹs expression?
hormone response element
tropic hormone
hormone that stimulates the secretion of another hormone
biochem deck
https://quizlet.com/152901264/biochemistry-flash-cards/
cranial nerves deck
https://quizlet.com/6321106/12-cranial-nerves-flash-cards/
nerve tracts deck
https://quizlet.com/7907988/chapter-16-17-nerve-tracts-and-the-autonomic-nervous-system-flash-cards/
somatotopic maps cards
https://quizlet.com/94470118/question-7-somatotopic-organization-flash-cards/
Regulation of insulin release by blood glucose levels is an example of
humoral control of hormone secretion
In specific defenses, B cells are responsible for ________ immunity, whereas cytotoxic T cells are necessary for ________ immunity.
humoral, cell-mediated
What is a condition where light, originating from a close up source, is focused behind the retina?
hyperopia
When potassium channels open, you have
hyperpolarization
When sodium channels close, you have
hyperpolarization
extrapyramidal tract
includes all pathways outside of the pyramidal tract. These tracts are comprised of indirect connections between the brain and spinal cord (the extrapyramidal tract does not directly synapse with motor neurons). The extrapyramidal tract is primarily involved in the control of large muscle groups and the maintenance of posture and balance.
Masses in the cytosol that contain glycgen are called
inclusions
How do alpha-glucosidase inhibitors decrease blood glucose levels?
inhibiting digestion of carbohydrates in the small intestine
What is the name of the enzyme that breaks down insulin in target cells?
insulin degrading enzyme
Why must insulin be injected into patients with diabetes mellitus type 1 as opposed to oral administration?
insulin would be degraded in the gastrointestinal tract and thus not absorbed
This cytokine inhibits cytokine production from macrophages to down-regulate the immune response.
interleukin-10
Secreted by helper T cells, this cytokine stimulates proliferation of helper T cells and cytotoxic T cells, proliferation and differentiation of B cells, and enhances the activity of natural killer cells.
interleukin-2
Anticodon
a sequence of three nucleotides forming a unit of genetic code in a transfer RNA molecule, corresponding to a complementary codon in messenger RNA.
What is triiodothyronine?
a thyroid hormone secreted from the thyroid gland
Inhibit brush border enzymes that hydrolyze disaccharides, trisaccharides, and oligosaccharides to glucose or other monosaccharides, thereby decreasing absorption of glucose
a-glucosidase inhibitors
Generates the mechanical force of a muscle through crossbridge cycling.
actin and myosin
Name the three proteins found in thin filaments.
actin, troponin, tropomyosin
What is a decrease in the amplitude of a receptor potential in the presence of a continuing stimulus called?
adaptation
The enzyme that catalyzes synthesis of cAMP is called ________ and is activated by ________.
adenylate cyclase : a Gs protein
The modality to which a receptor responds best is called the ________.
adequate stimulus
The stimulus type to which a receptor responds to greatest.
adequate stimulus
Which of the following endocrine glands is innervated by sympathetic preganglionic neurons?
adrenal medulla
What are proteins called that have been glycosylated through a non -enzymatic process?
advanced glycosylation end products
The amplitude of a sound wave is determined by the difference in the ________.
air molecule density in the compressed versus rarified regions of the sound wave
What is the primary protein that appears in the urine with nephropathy?
albumin
Which adrenergic receptor(s) has the greatest affinity for norepinephrine?
alpha and beta 1
Glucagon is made in the
alpha cells of the pancreas
Activation of which class of adrenergic receptor will result in calcium release from intracellular stores?
alpha1 only
Actions at which class of adrenergic receptor generally have excitatory effects?
alpha1, alpha2, beta1, and beta3
Activation of which class of adrenergic receptor decreases the cytosolic levels of cAMP?
alpha2 only
Which of the following describes the signal transduction mechanism for estrogen, a steroid hormone?
altering transcription of mRNA
A secondary endocrine organ is ________.
an organ that secretes hormones, but is better known for another function
Name the two types of sensory endings found in muscle spindles.
annulospiral endings, flower-spray endings
Relative to the triceps muscle, the biceps is its ________.
antagonist
What nourishes the lens and cornea?
aqueous humor
Brocaʹs area and Wernickeʹs area are regions important in language that are connected by the
arcuate fasciculus
The hair cells are embedded within endolymph, thus, when a potassium channel opens, potassium moves ________ the cell, causing it to ________.
into : depolarize
Inclusions are
intracellular stores of glycogen or triglycerides
What is mitral valve prolapse?
inversion of the left AV valve
What are epidermal cells that proliferate to cover the opening of a wound?
keratinocytes
__________ cells contain insulin-degrading enzyme.
kidney
As the intensity of exercise increases, the muscles switch from oxidative to substrate-level phosphorylation, resulting in the increased generation of which of the following?
lactic acid
Heavy intensity exercise generates what by-product that contributes to fatigue?
lactic acid
Which of the following best describes the relationship between motor neuron size, motor unit size, and order of recruitment?
large motor neurons : large motor unit : last to be recruited
The time between the occurrence of an action potential in skeletal muscle and the onset of tension is called what?
latent period
Which chamber of the heart has the thickest musculature?
left ventricle
The refractive power of this structure can be altered to focus light.
lens NOT pupil
The saccule detects what type of motion?
linear acceleration up or down
Which of the following is a property of isometric skeletal muscle contraction?
load is greater than the force generated by the muscle
Which of the following is a property of isotonic skeletal muscle contraction?
load is less than the force generated by the muscle
Which of the following statements about lateral inhibition is FALSE?
location of the cell body of the afferent neuron
Frequency of sound is coded for by ________.
location of the hair cell stimulated.
The delay between release of a steroid hormone and an observable response from the target cell tends to be quite (long / short) compared with protein hormones that bind to receptors on the cell membrane.
long
The ________ is the interior compartment of a hollow organ or vessel
lumen
Name the three ossicles in the middle ear.
malleus, incus, stapes
Leukocyte movement from blood to the site of tissue damage or infection involves ________, leukocyte movement toward the blood vessel wall; ________, the movement of leukocytes between endothelial cells of the blood vessel; and ________, the movement within the tissue to the site of injury.
margination, diapedesis, chemotaxis
What type of vision occurs in light levels that activate both rods and cones?
mesopic
Is the NMDA receptor ionotropic or metabotropic
metabotropic
The action of adrenergic receptors identifies them as ________ receptors.
metabotropic
Name the four types of fixed macrophages.
microglia, alveolar macrophages, Kupffer cells, and histiocytes
Which filament is found in cilia and flagella?
microtubules only
Hormones that are dissolved in blood typically exhibit a half-life on the order of ________, whereas hormones that are bound to carrier proteins can remain undegraded for ________.
minutes, hours
In what class of neuron and within what organelle is the enzyme monoamine oxidase located?
mitochondria of sympathetic postganglionic neurons
The second-order neurons in the olfactory pathway are called ________.
mitral cells
First-order olfactory neurons synapse with ________. These synapses occur in clusters called ________.
mitral cells, glomeruli
catecholamines are degraded by _________ and ___________
monoamine oxidase (MAO) and catechol-O-methlytransferase (COMT). MAO and COMT are located within the synaptic cleft, while MAO is also found in the axon terminal and some glial cells.
Contraction of skeletal muscle fibers is stimulated by what type of neuron?
motor neurons
The anterior portion of the semicircular canal detects acceleration in which direction?
moving the head up and down as in saying yes
Corrective lenses that are concave are used to correct
myopia
Enzyme that modulates the ability of myosin to bind actin in smooth muscle.
myosin light chain kinase
Identify the two classes of input that can alter the secretion of hormones.
neural signals and humoral signals
Amputation in diabetics is often secondary to what other problem with diabetes?
neuropathy
The gate-control theory of pain modulation states that ________.
non-painful somatic signals can inhibit signals of pain
When glucose levels exceed 600 mg/dL, a _____________ can occur
nonketotic coma
Released from varicosities in the sympathetic nervous system.
norepinephrine
The α1 adrenergic receptor has the greatest affinity for what messenger?
norepinephrine
Which of the following describes second degree heart block?
not every atrial contraction is followed by a ventricular contraction
is calcium greater inside the cell or outside
outside
is Cl- greater inside the cell or outside
outside (but chemical and electrical gradients are opposed
Contain myoglobin
oxidative
lactate dehydrogenase
oxidizes NADH to NAD+, replenishing the oxidized coenzyme for glyceraldehyde-3-phosphate dehydrogenase.
The relative color (depth of redness) of blood is a direct indication of the amount of ________ bound to hemoglobin.
oxygen
What hormone released by the posterior pituitary functions in uterine contraction and milk letdown in the breast?
oxytocin
(sympathetic/parasympathetic/both/neither) Releases acetylcholine from its postganglionic fibers.
parasympathetic
Ciliary muscle is innervated by what branch of the nervous system? A) somatic nervous system B) enteric nervous system C) sympathetic nervous system D) parasympathetic nervous system E) central nervous system
parasympathetic nervous system
The circular muscles of the iris are innervated by the ________ nervous system and their contraction causes pupillary ________.
parasympathetic, constriction
Gustatory cortex
parietal lobe
Somatosensory cortex.
parietal lobe
Which of the following is the correct order of communication of visual information in the retina?
photoreceptor, bipolar cell, ganglion cell
Arrange the following components of the neural pathway for vision in the correct order starting with the photoreceptor and ending with the visual cortex: photoreceptor, optic radiations, optic tract, ganglion cell, bipolar cell, optic nerve, optic chiasm, lateral geniculate body, visual cortex.
photoreceptor, bipolar cell, ganglion cell, optic nerve, optic chiasm, optic tract, lateral geniculate body, optic radiations, visual cortex
When a B cell contacts a foreign or abnormal antigen, it develops into a ________ that releases ________.
plasma cell, antibodies
______ secretes antibodies
plasma cells
Slow pain is mediated by what type of nociceptor?
polymodal nociceptors
Closure of the atrioventricular valve occurs when ________.
pressure inside the ventricle is greater than pressure inside the atrium
Origin of the pyramidal tract.
primary motor cortex
What enzyme is activated by cAMP?
protein kinase A
Under hyperglycemic conditions, what causes mesangial cells to secrete excess extracellular matrix in kidneys?
protein kinase C
When associated with G protein, guanylate cyclase will activate what enzyme?
protein kinase G
What is a region of skin that, when activated, will result in the change of activity within a particular afferent neuron?
receptive fields
Which of the following does NOT influence the force generated by an individual muscle fiber?
recruitment
Which is the longest phase of a twitch?
relaxation
Comprised of neural tissue that includes bipolar cells.
retina
The posterior portion of the semicircular canal detects acceleration in which direction?
rotation of the head from side to side, as in moving the ear toward the shoulder
(Dihyropyridine / Ryanodine) receptors are located on the sarcoplasmic reticulum.
ryanodine
Calcium is stored in what region of skeletal muscle cells?
sarcoplasmic reticulum
What is a biogenic amine that is NOT classified as a catecholamine?
serotonin
Fast pain originating from nociceptors is perceived as a ________ pain and is carried along ________ fibers.
sharp, a delta
In diabetes mellitus type 1, blood vessel damage occurs primarily through what process?
shear stress on the blood vessels due to elevated pressure
(Single-unit / Multi-unit) smooth muscle contains pacemaker cells.
single unit
Calcium binds to troponin.
skeletal and cardiac muscle only
Thick and thin filaments organized into sarcomeres.
skeletal and cardiac muscle only
The somatic nervous system regulates the activity of ________.
skeletal muscle
Glucose is stored in the form of glycogen primarily within what two organs?
skeletal muscle and liver
Calcium for contraction comes entirely from the sarcoplasmic reticulum.
skeletal muscle only
Thermoreceptors have relatively (large / small) receptive fields.
small
The mechanism responsible for the size principle involves ________.
smaller motor neurons that contain the least number of muscle cells and reach threshold easier than larger neurons
Gap junctions present between cells.
smooth and cardiac muscle only
Innervated by autonomic nervous system.
smooth and cardiac muscle only
What causes the rapid depolarization phase of a contractile cell action potential?
sodium movement into the cell
Sensory information about (vision / sound) is relayed through the medial geniculate body of the thalamus
sound
Location of the dorsal columns
spinal cord
Where the spinothalamic tract crosses over to the opposite side.
spinal cord
Which of the following could cause a pacemaker potential?
spontaneous opening of sodium channels
The ________, projecting from the end of hair cells, are attached to the ________, which causes them to bend when sound waves enter the cochlea.
stereocilia : tectorial membrane
All hormones of the adrenal cortex are
steroid hormones
In addition to an increase in sensitivity to glutamate, the binding of large amounts of glutamate to its receptors on the postsynaptic membrane also ________.
stimulates the release of a paracrine messenger that further increases glutamate release
Cardiac muscle is (smooth / striated).
striated
The end-diastolic volume minus the end-systolic volume is the ________.
stroke volume
During ________, a phosphate group is transferred from a metabolic intermediate to an ADP to synthesize ATP.
substrate level phosphorylation
In skeletal muscle, ATP can be synthesized by transferring a phosphate group from creatine-P to ADP to form ATP and creatine. In this example, ATP was synthesized by what process?
substrate-level phosphorylation
What diabetes medication stimulates insulin release from beta cells of the pancreas?
sulfonureas
What drug class used originally to treat typhoid fever during World War II is now used to treat diabetes mellitus type 2
sulfonureas
Which of the following structures of an autonomic neuron is NOT located within the ganglion?
the cell body of preganglionic neurons
How are pain signals from visceral receptors referred to the body surface?
the convergence of visceral and somatic afferents on the same second-order neurons
The body is able to synthesize the amino acids glutamate, aspartate, and glycine from
the degradation of glucose in glycolysis and the Krebs cycle
what happens if the pyramidal tract is damaged?
the extrapyramidal tracts will take over some functions (and vice versa)
Depolarization of hair cells in the utricle occurs when ________.
the hair cell bends toward the kinocilium
during first degree heart block
the heart's electrical signals are slowed as they move from the atria to the ventricles (the heart's upper and lower chambers, respectively). This results in a longer, flatter line between the P and the R waves on the EKG (electrocardiogram).
What happens when excessive angiogenesis occurs?
the new blood vessel walls are weak and tend to leak
What causes the sounds that one hears as the heart beats?
the turbulence created as the valves close
Blood is ejected from the left ventricle once pressure within ________.
the ventricle is greater than pressure within the aorta
Where do the preganglionic neurons of the sympathetic nervous system emerge from the spinal cord?
thoracic and lumbar regions
In order to be completely functional, a T cell must be activated by ________.
thymus gland
The thyroid gland secretes what hormone?
thyroid hormones and calcitonin
Along a large portion of the retina, light must pass through _____ layers of cells before reaching a photoreceptor.
two
Which of the following best describes the general arrangement of the efferent limb of the autonomic nervous system?
two neurons in series
Transmits sound energy from the outer ear to the middle ear.
tympanic membrane
Cells that secrete dopamine must contain which enzymes?
tyrosine β-hydroxylase and dopa decarboxylase
Detects linear acceleration
utricle
Hormones released from the anterior pituitary
"FLAT PiG" FSH LH ACTH TSH Prolactin insulin Growth hormone
What cells of the adrenal medulla secrete catecholamines?
chromaffin cells
What cells secrete epinephrine from the adrenal medulla?
chromaffin cells
T/F The speed with which smooth muscle cells contract is similar to fast glycolytic skeletal muscle cells.
False
This step is enhanced by the presence of opsonins.
clearance of the infection by phagocytosis
T/F Skeletal muscle fibers are formed by the fusion of multiple cells during embryonic development, resulting in the presence of numerous nuclei per fiber.
True
T/F Some visceral reflexes are spinal reflexes.
True
Appears as dark bands under the microscope.
A band
T/F Sympathetic preganglionic neurons traveling to collateral ganglia travel through ganglia of the sympathetic trunk without making synaptic communication.
True
T/F The antigen receptors on T cells come from the same family of proteins as antibodies.
True
How is a reflex that involves signals sent along autonomic sensory nerves classified?
Visceral
Neuropeptide neurotransmitters
ACTH, Cholecystokinin, Dynorphin, Endorphins, Enkephalins, Glucose-dependent insulinotropic peptide (GIP), Glucagon, neurotensin, oxytocin, secretin, substance-p, thyrotropin releasing hormone (TRH), vasopressin, and VIP
At what age do symptoms of diabetes mellitus type 1 first appear?
After age 7
What hormone is secreted by the heart?
Atrial Natriuretic Peptide (lowers blood pressure and to controls electrolyte homeostasis)
(Agglutination / Opsonization) is dependent on antibodies being capable of binding more than one antigen.
Agglutination
What are coenzymes
organic molecules derived from vitamins that function in the transfer of a chemical group
What is the site where a muscle attaches to a stationary bone called?
origin
Which of the following is responsible for the rapid depolarization phase of an action potential within the pacemaker cells?
An increase in PCa
Which of the following is responsible for the repolarization of pacemaker cells?
An increase in Pk
During near vision, the ciliary muscle (contracts/relaxes) due to activation of the (sympathetic/parasympathetic) nervous system. As a result, the zonular fibers to go (taut/slack), which causes the refractive power of the lens to (increase/decrease) and the lens become (flatter/rounder).
Answer: contracts : parasympathetic : slack : increase : rounder
In skeletal muscle, at lengths less than the length that generates maximum active tension, is active tension less than, greater than or equal to total tension?
Approx the same b/c passive tension is negligible.
Eicosanoids are derived from what phospholipid?
Arachidonic acid
reflex categories
As such, reflexes can be distributed into four categories: spinal vs. cranial (depending upon the region of the nervous system where responses are integrated), somatic vs. autonomic (depending upon the efferent pathway that is activated), conditioned vs. innate (depending upon whether they are learned or not), and monosynaptic vs. polysynaptic (the number of synapses in the pathway).
T/F Passive immunization induces long-term immunity.
False
T/F Receptive field sizes are approximately the same over all parts of the body for a specific modality.
False
________ are proteins attached to intermediate filaments in regions where cells are exposed to mechanical stresses.
Cadherins
capillaries dilate and become more permeable
Caused by histamine released from mast cells.
T/F Skeletal muscle and cardiac muscle are multinucleated cells, whereas smooth muscle cells each have one nucleus.
False
How is a reflex that requires communication with the brain classified?
Cranial
T/F The complement system can be activated by IgM, IgG, and IgA.
False
Which of the following is NOT a specialization observed at the neuromuscular junction?
Each muscle fiber is innervated by multiple motor neurons.
(T/F) Endocrine glands secrete neurohormones.
F
T/F Diabetes mellitus requires insulin injections for maintenance
F
T/F Exocrine glands secrete hormones.
F
T/F Fatty acids are ampiphatic
F
Which of the following molecules is NOT converted to glucose through the process of gluconeogenesis? A) glycerol B) lactate C) amino acids D) pyruvate E) fatty acids
Fatty acids
pancreatic polypeptide
Inhibits Somatostatin, gall bladder secretion, and secretion of digestive enzymes Made in the F cells of the pancreas
Additional leukocytes are recruited to the region
Involves adhesion molecule expression in blood vessel walls and leukocytes.
What is special about the P site of a ribosome?
It holds the tRNA with the most recent amino acid that HAS BEEN ADDED to the polypeptide chain.
What organ contains glucose-6-phosphatase?
Liver
Anchors thick filaments together.
M line
Where is pyruvate converted to acetyl CoA
Mitochondrial matrix
________ is composed of nucleotide polymers with the phosphate of one nucleotide bound to the ribose sugar of another.
Ribonucleic acid, NOT deoxyribonucleic acid
What type of glial cell is located in both the central nervous system and the peripheral nervous system?
NONE
Adrenergic neurons synthesize
Norepi, L-Dopa, Dopamine
What is the difference between diabetes mellitus and diabetes insipidus?
One is a deficit in insulin activity, the other a deficit in ADH activity.
Is magnesium greater inside or outside of the cell
Outside
When insulin is first translated by ribosomes, the initial inactive polypeptide that is formed is called
Preproinsulin
What is ICF rich in?
Proteins and potassium
PFK 1
Rate-limiting enzyme in glycolysis, inhibited by ATP and citrate, activated by AMP. F-6-P --> F-1,6-BP.
Which of the following is NOT part of the process whereby skeletal muscles relax?
Sarcolemmal calcium channels open to allow the efflux of calcium.
Which of the following is NOT a possible destination for proteins synthesized on ribosomes free in the cytosol? A) remains in cytosol B) peroxisome C) mitochondrion D) nucleus E) secreted from the cell
Secreted from cell
Flagella
Similar in structure to cilia, but longer
What class of TRP channels responds to menthol?
TRPV3
T/F Drugs like cyclosporin A are given to transplant patients to inhibit the production of interleukin-2 and thereby inhibit the immune response.
True
T/F Eosinophils are phagocytes that also attack parasites.
True
phosphoenolpyruvate
Substrate level phosphorylation, generates ATP, converted from 1,3-BPG
(T/F) All catecholamine-secreting cells synthesize dopamine
T
Passive tension (muscles)
Tension developed by simply stretching a muscle to different lengths.
Total tension (muscles)
Tension developed when a muscle is stimulated to contract at different preloads. It is the sum of the active tension developed by the cross-bridge cycling in the sarcomeres and the passive tension caused by stretching the muscle.
T/F Information from the right visual field is perceived in the left visual cortex
True
Which of the mechanisms listed below does NOT account for the decrease in force development by muscle cells during sustained force development?
The crossbridges can become resistant to ATP.
T/F Merkel's disks are superficial mechanoreceptors located in both glabrous and hairy skin.
True
What is the significance of Coxsackie B virus in diabetes mellitus type 1?
This virus attacks beta cells of the pancreas causing an immune response against these cells.
What cells of the adrenal medulla release epinephrine?
chromaffin cells
What is silent myocardial ischemia?
a heart attack without pain
The ____ is the site of rRNA production
nucleolus
The optic nerve exits the eye at this point.
optic disk
What two taste qualities use a G protein during the transduction process?
sweet, bitter
Aldosterone is secreted by which layer(s) of cells within the adrenal cortex?
zona glomerulosa
What layer of the adrenal cortex secretes mineralocorticoids?
zona glomerulosa
Discuss the structure and function of the pituitary gland, with special emphasis on the hormones released from the posterior pituitary.
-attached to the brain by the infundibulum. cell bodies are in the hypothalamus -anterior portion (adenohypophysis) and a posterior portion (neurohypophysis) -The posterior portion contains the nerve endings that originate within the hypothalamus. -The two peptide hormones released from the posterior pituitary are antidiuretic hormone (ADH or vasopressin) and oxytocin. ADH is synthesized in the paraventricular nucleus of the hypothalamus, while oxytocin is synthesized in the supraoptic nucleus of the hypothalamus. Following their synthesis, ADH and oxytocin are transported along the nerves within the infundibulum to the posterior pituitary, from which they are released. -Hypothalamic-pituitary portal system = capillary bed that first drains the hypothalamus.
The rapid depolarization phase of a contractile cell is also known as phase ________.
0
Sequence of events in NMJ
1) Action potential travels down the motoneuron to the presynaptic terminal. 2) Depolarization of the presynaptic terminal opens Ca2+ channels, and Ca2+ flows into the terminal. 3) Acetylcholine (ACh) is extruded into the synapse by exocytosis. 4) ACh binds to its receptor on the motor end plate. 5) Channels for Na+ and K+ are opened in the motor end plate. 6) Depolarization of the motor end plate causes action potentials to be generated in the adjacent muscle tissue. 7) ACh is degraded to choline and acetate by acetylcholinesterase (AChE); choline is taken back into the presynaptic terminal on an Na+-choline cotransporter.
Describe the general properties of the body s internal nonspecific defenses.
1) Skin and mucous membranes, secretion from sebaceous and sweat glands 2) The inflammatory response is initiated by macrophages --> increased blood flow. 3) Blood flow --> increased permeability of capillary endothelial cells. This recruits additional leukocytes to the site of infection, and isolates the infected material by the release of clotting factors. 4) Release of interferons (a and )b by virus-infected cells. Interferons act on nearby cells, making them resistant to viral replication due to the presence of RNA-degrading enzymes. Thus, while the virus-infected cells will die, the cells surrounding them are protected from infection. Another type of interferon (y ) is secreted from T cells and NK cells, and activates cytotoxic T cells and NK cells to kill virus-infected cells and cancer cells. 5) Natural killer (NK) cells that recognize the general features of infected cells and cause them to lyse. The activity of the NK cells is enhanced by interleukin-2 and antibodies. 6) The complement system is a form of nonspecific defense that involves a cascade of proteins. Those proteins lead to the incorporation of a membrane attack complex (MAC) into bacteria, causing them to lyse. 7) The complement system can be activated by either the alternative or classical pathways. The alternative pathway is activated by directly binding to carbohydrates on the bacterium. The classical pathway is activated by the binding of an antibody to bacteria. Some complement proteins also play a role in chemotaxis or bind to mast cells to stimulate histamine release. At the same time, the complement protein C3b attaches to the surface of bacteria to induce opsonization, which enhances bacterial degradation by phagocytosis.
Put the steps for initiating translation in order:
1. Binding of small ribosomal subunit to mRNA. 2. Binding of initiator tRNA to mRNA. 3. Binding of large ribosomal subunit to mRNA. 4. Binding of tRNA with 2nd amino acid to the A site. 5. Formation of covalent bond between methionine and second amino acid.
How many ATP are produced for each acetyl coenzyme A completely catabolized in the presence of oxygen?
12
In an ECG recording, the RR interval is 0.5 seconds. What is the heart rate?
120 beats/min
For each FADH2 that supplies electrons to the electron transport system, ________ ATP(s) is/are synthesized. For each NADH + H+ that supplies electrons to the electron transport system, ________ ATP(s) is/are synthesized.
2, 3
Up to ______ of the brainʹs energy substrate can be supplied by ketones, but _____ must still be derived from glucose.
2/3rds, 1/3rd
What are the functions of the 5' cap and 3' poly A tail respectively
5' cap is for initiation of translation 3' poly A tail is for stabilizing mRNA so it is not degraded in the cytoplasm.
Which of the following are indicative of the relative release of catecholamines from the adrenal medulla?
80% norepi, 20% epi
Extends the length of the thick filaments.
A band
what is a secondary lysosome
A lysosome that has fused with a phagosome
While muscle cells respond in an all-or-nothing manner to a single action potential, the extent of force that they generate can be modified by a number of factors. Describe the mechanisms whereby individual skeletal muscle cells can modify force development.
A muscle response to frequency contains two components: the treppe phenomena and the summation of contraction. Treppe describes the phenomena where an increase in frequency of stimulation (with complete relaxation between pulses) will progressively increase the force developed by the muscle until force ultimately stabilizes. The explanation for this phenomena involves an increasing concentration of intracellular calcium, due to incomplete removal of calcium during relaxation, which elevates the force developed by the muscle cell. Summation of contraction is observed as the frequency of stimulation increases further, such that the muscle cell does not completely relax between twitches. As the frequency of twitches increases, the first twitch will not completely relax before the second twitch arrives, and so on. Thus, as frequency increases, the force generated by the muscle would continue to increase until a maximum is reached. As the frequency of stimulation increases, the muscle will eventually be able to maintain force with some oscillation around a constant value. This oscillation in force is termed tetanus. As frequency is increased further, force will eventually plateau (the trace flattens and there is no relaxation between twitches) into what is called fused (complete) tetanus or maximal tetanic tension. Prior to this force plateau (fusion), force fluctuates as the muscle cell partially relaxes between twitches, which is called unfused (incomplete) tetanus. Second, the force developed by a muscle fiber is dependent upon the diameter of that muscle fiber. As the diameter of a muscle fiber increases (number of parallel sarcomeres increases), the force generated by that muscle will increase. Finally, skeletal muscle length will affect the extent of tension development by the muscle cell. Typically, the muscle rests at near optimal length for force development. As the muscle is lengthened, the potential for interaction between actin and myosin is reduced as they slide past one another, thereby causing the force generated by the muscle to decrease. As the muscle is shortened, the extent of interaction will also be reduced by the thin filament blocking the binding of myosin and actin. In this case, force is also decreased as the muscle is shortened.
Which of the following statements about excitation-contraction coupling in skeletal muscle is FALSE? A) An action potential in the sarcolemma stimulates the opening of voltage-gated calcium channels in the plasma membrane and the sarcoplasmic reticulum. B) Calcium binds to troponin, causing a shift in tropomyosin thereby exposing the binding sites on actin for myosin. C) DHP receptors on the T tubules detect changes in voltage and communicate to ryanodine receptors on the sarcoplasmic reticulum to open calcium channels. D) An end-plate potential triggers an action potential on the sarcolemma. E) Calcium ATPases in the sarcoplasmic reticulum are necessary for relaxation of the muscle.
A) An action potential in the sarcolemma stimulates the opening of voltage-gated calcium channels in the plasma membrane and the sarcoplasmic reticulum.
Polysaccharides on bacterial cells stimulate the production of antibodies by binding to ________. A) B cells that stimulate plasma cell proliferation B) B cells that stimulate plasma and memory cell proliferation C) helper T cells that release interleukin-1 to stimulate plasma cell proliferation D) helper T cells that directly stimulate plasma and memory cell proliferation E) B cells that release interleukin-2 to stimulate plasma cell proliferation
A) B cells that stimulate plasma cell proliferation
The ________ protein on the cytotoxic T cell binds to the ________ major histocompatibility (MHC) molecule on the infected cell. A) CD8 : class I B) CD8 : class II C) CD4 : class I D) CD4 : class II E) CD6 : class I
A) CD8: class I
Which of the following interleukins (IL) is NOT targeted to B cells? A) IL-10 B) IL-2 C) IL-4 D) IL-5 E) IL-
A) IL-10
Which of the antibody classes is able to destroy an antigen by activating the nonspecific killing action of the natural killer cells? A) IgG only B) IgM only C) IgE only D) both IgG and IgM E) both IgM and IgE
A) IgG only
Which of the following is NOT a characteristic of a primary immune response? A) The response is especially strong. B) Antigen selected B or T cells proliferate. C) Antigen selected B or T cells differentiate into effector cells. D) It requires 10-17 days to initiate. E) The response is short-lived.
A) The response is especially strong.
Cells that leave the thymus with the ability to bind to class I major histocompatibility (MHC) molecules will develop into ________. A) cytotoxic T cells B) B cells C) helper T cells D) suppressor T cells E) macrophages
A) cytotoxic T cells
Which of the following is characteristic of diabetic cardiomyopathy? A) decreased stroke volume B) decreased heart rate C) decreased size of the heart D) decreased likelihood of myocardial infarction E) All of the above
A) decreased stroke volume
Interferons and are released from ________ and act to inhibit viral replication by ________. A) infected cells : degrading RNA B) neutrophils : digesting the virus C) phagocytotic cells : digesting the virus D) phagocytotic cells : degrading RNA E) T lymphocytes : degrading RNA
A) infected cells, degrading RNA
Hay fever that occurs when people are exposed to pollen involves an excess release of IgE, which binds to ________ and causes them to ________. A) mast cells : degranulate, releasing histamine B) pollen : stimulate the release of histamine C) macrophages : destroy the pollen whose by-products stimulate histamine release D) T helper cells : stimulate the proliferation of cytotoxic T cells E) mast cells : stimulate the proliferation of cytotoxic T cells
A) mast cells : degranulate, releasing histamine
Histamine acts as a(n) ________ in its role in inflammation. A) paracrine B) autocrine C) hormone D) neurotransmitter E) cytokine
A) paracrine
Cytotoxic T cells release two proteins to destroy infected cells: ________, which forms pores in the membrane of the infected cells, and ________, which enters the infected cell through these pores and triggers apoptosis. A) perforins : fragmentins B) fragmentins : perforins C) MHC class I : MHC class II D) complement system proteins : perforins E) complement system proteins : fragmentins
A) perforins: fragmentins
The increase in blood flow to a site of infection acts to ________.
A) recruit more leukocytes to the site of infection
Which of the following is NOT one of the important properties of the immune system that results from the action of B and T cells? A) redundancy B) specificity C) diversity D) memory E) self-tolerance
A) redundancy
Vaccines are composed of ________ that stimulate an active immunity to the pathogen. A) the non-pathogenic portion of the microorganism B) the pathogenic portion of the microorganism C) antibodies to a microorganism D) memory B cells that respond to a microorganism E) memory T cells that respond to a microorganism
A) the non-pathogenic portion of the microorganism
A neurohormone is (ADH / acetylcholine), which is released from the (kidney / pituitary gland).
ADH, pituitary
Following death, rigor mortis occurs due to a lack of (calcium / ATP).
ATP
Conduction through which of the following is slow to allow atria to contract before the ventricles?
AV node
Chordae tendinae are strands of connective tissue extending from ________ to ________
AV valves, papillary muscle
Most common neurotransmitter in the PERIPHERAL nervous system.
Acetylcholine
Which of the following is located between the invaginations of the motor end plate of a neuromuscular junction?
Acetylcholinesterase
Which of the following best describes the function of transverse (t) tubules and the sarcoplasmic reticulum in skeletal muscle contraction?
Action potentials in T tubules are detected by DHP receptors, which are coupled to ryanodine receptors in the sarcoplasmic reticulum and open channels for calcium.
Describe the two types of pain and the difference between discriminative and affective pain. Describe the gate-control theory of pain modulation.
Activation of nociceptors leads to the perception of pain. That perception of pain can lead to several possible responses that include a reflex withdrawal from the stimulus, increased autonomic response, or an emotional response. We perceive pain in two ways, which are termed as fast pain and slow pain. Fast pain is perceived as a sharp, pricking sensation that can be easily localized and is transmitted over A fibers. Slow pain is detected as a poorly localized, dull ache that is transmitted over C fibers. The primary afferents from nociceptors synapse with second-order receptors in the spinal cord. The discriminative properties of pain relate directly to our perception of pain. At the same time, activation of that pathway will stimulate (coactivate) a second pathway that assesses the affective component of the painful stimulus. The affective component of a painful stimulus is the aspect of pain that is not associated with the pain itself, as in the case of an autonomic or emotional response to pain. The pathway utilized by the affective components of pain ascend through the reticular formation of the brainstem, to the hypothalamus, and to the limbic system. The gate-control theory of pain modulation maintains that a non-painful somatic stimuli can inhibit pain signals at the level of the spinal cord. There are many interneurons within the spinal cord; one type of these is inhibitory for second-order nociceptive neurons. If this interneuron is active, then the transmission of the painful message will be diminished and the perception of pain will be lessened. The inhibitory interneuron is activated by A fibers (associated with mechanical stimuli) and inhibited by collaterals from C fibers (nociceptors). However, when the two neuronal tracts are activated, collaterals from the A fibers will stimulate the inhibitory interneuron, thus decreasing the transmission of the painful message.
Name a protein in the blood that is relatively non-specific with respect to its ability to bind and transport chemical messengers in the blood.
Albumin
Which of the following statements is TRUE regarding activation of alpha and gamma motor neurons?
Alpha and gamma motor neurons are activated at the same time.
In order for skeletal muscle to develop force, a muscle cell must be able to convert the action potential generated at a neuromuscular junction into crossbridge cycling. Describe the process of excitation-contraction coupling in skeletal muscle, including all of the important ion channels and the structures involved in this process.
An action potential is generated at the motor end plate by the binding of acetylcholine to the nicotinic receptor. That action potential travels along the sarcolemma and down the transverse tubules. Located within the membrane of the transverse tubules are dihydropyridine receptors that are voltage sensitive. These receptors are usually activated by depolarization. The membrane of the transverse tubule comes into contact with the sarcoplasmic reticulum, allowing the dihydropyridine receptor to directly interact with the ryanodine receptor on the sarcoplasmic reticulum. When the dihydropyridine receptor is activated by membrane depolarization from the action potential, the ryanodine receptor is stimulated to release calcium from the sarcoplasmic reticulum. As intracellular calcium increases, the release of calcium is enhanced by the binding of calcium to another calcium channel on the sarcoplasmic reticulum. In addition to their proximity to the transverse tubule, the sarcoplasmic reticulum is positioned near contractile proteins of the sarcomere to facilitate the delivery of calcium to those contractile proteins. As calcium increases within the cell, it binds to a subunit of the troponin molecule. This binding causes a conformational change in the other two troponin subunits that move the filamentous tropomyosin. At rest, tropomyosin blocks the myosin binding site on the actin molecules. Thus, the movement of tropomyosin exposes the binding site that would allow the energized myosin to interact with actin.
All receptors, by definition, must transduce the energy from a stimulus into an electrical signal before that information can be sent to the central nervous system. Once that electrical signal is generated, how does the brain decode the type, intensity, duration, and location of a stimulus?
Answer: Our perception of a stimulated receptor is based upon the sensory pathway activated and the region of the brain where those pathways terminate. Thus, activation of an auditory neuron will result in the perception of sound independent of how that neuron was activated. The specific pathway that transmits information is referred to as labeled lines, with each sensory receptor having its own unique labeled line. Stimulus intensity is coded for in two ways: 1) action potential frequency (frequency coding) and 2) the number of receptors activated (population coding). As stimulus intensity increases, the magnitude of the graded potential will increase, resulting in more frequent action potentials (increased frequency). Alternatively, a stronger stimulus could activate more receptors. The number of receptors activated depends upon the size and density of each receptor s receptive field. Slowly adapting receptors work best for coding intensity while rapidly adapting receptors are better for coding change (not magnitude of change). The location of a stimulus is coded by location of their receptive field. The precision with which we can perceive location is called acuity. Acuity for a particular stimulus will depend upon a receptive field s size, number of receptors, the extent of overlap, and its lateral inhibition. These can vary considerably between receptive fields throughout the body. Lateral inhibition describes a situation where input from a strongly stimulated receptor will inhibit the afferent pathway transmitting information from nearby receptors.
Why do AV nodal cells NOT determine the heart rate?
As depolarization initiated in the SA node reaches the AV node, it leaves the AV node in a refractory state.
Describe the process involved in focussing an image onto the retina for objects near and far and how that process is controlled. Identify the two common defects in our ability to focus light on the retina and how they can be fixed.
As light moves from one transparent material to the next (cornea aqueous humor lens vitreous humor), those wavelengths of light are bent (refracted). Light is refracted as it moves through the interface of two transparent materials of different densities. In the human eye, the lens is capable of actively modifying its refractive power through accommodation (the process of modifying the structure of the lens). The thickness of the lens can be altered by ciliary muscles that are attached to the lens by zonular fibers. The ciliary muscle forms a ring around the lens such that, when it contracts, the amount of tension on the lens from the zonular fibers is reduced. This reduction in radial tension on the lens causes the lens to thicken due to its inherent elasticity. As the lens thickens, light is bent to a greater extent in order to focus objects that are close to the eye onto the retina. When viewing something at a distance, the ciliary muscle relaxes, which increases the tension on the zonular fibers and thereby causes the lens to flatten. Accommodation is under the control of the parasympathetic nervous system, whose activity stimulates ciliary muscle contraction, causing the lens to thicken as it focuses on an object that is near. A distant object is brought into focus by the relaxation of the ciliary muscle induced by a decrease in parasympathetic activity. However, the lens is not always able to focus the light onto the retina. In myopia (near-sightedness), the lens and cornea refract the light such that the image is focused in front of the retina. This can be corrected by positioning a concave lens in front of the cornea, which will cause the light to diverge before reaching the eye. Hyperopia occurs because the lens cannot accommodate enough for near vision (the light is not refracted enough). Thus, the object is focussed behind the retina. A convex lens in front of the cornea can correct for this by causing the light to converge before reaching the eye.
The potassium equilibrium potential is -94 mV. What does this means?
At -94 mV, the chemical force for potassium movement is opposed exactly by the electrical force
The inhibition of interleukin-2 synthesis by cyclosporin A and other anti-rejection drugs will act to inhibit the activity of what type(s) of cell?
B cell and T cell
Which of the following is NOT characteristic of slow-wave sleep? A) decreased muscle tone B) elaborate and intense dreams C) snoring D) decreased brain activity E) increased parasympathetic activity
B elaborate and intense dreams
Why is a secondary immune response stronger? A) Effector cells produced during the primary response are still present circulating in the blood. B) Memory cells produced during the primary response lead to a rapid proliferation of effector cells on subsequent exposure to the antigen. C) Antibodies produced during the primary response are still present circulating in the blood. D) Body cells develop resistance to the pathogen. E) Body cells are primed to produce antibodies against the pathogen.
B) Memory cells produced during the primary response lead to a rapid proliferation of effector cells on subsequent exposure to the antigen.
Which of the following is the property of skeletal muscle whereby an increase in the frequency of action potentials enhances the force developed by the muscle cell? A) Length-tension relationship B) Summation C) Force-velocity relationship D) External tension E) Internal tension
B) Summation
Which of the following best describes an isotonic contraction? A) When the contractile elements shorten, they lengthen the elastic elements but do not move the load. B) When the contractile elements shorten, they create enough force to move the load. C) When the contractile elements lengthen, they shorten the elastic elements and move the load. D) When the contractile elements lengthen, they lengthen the elastic elements but do not move the load. E) The contractile elements stay the same length as the elastic elements shorten and move the load.
B) When the contractile elements shorten, they create enough force to move the load.
Which of the following is NOT an integral membrane protein? A) tyrosine kinase B) calmodulin C) G proteins D) adenylate cyclase E) phospholipase C
B) calmodulin
The process of clonal selection gives rise to short-lived clones called ________, which combat the antigen that stimulated their production. A) memory cells B) effector cells C) antibodies D) antigens E) helper cells
B) effector cells
In the end, the complement system destroys invading bacteria by ________. A) phagocytosis B) forming a membrane attack complex C) release of lytic enzymes D) agglutination E) neutralization
B) forming a membrane attack complex
63) While some of the daughter helper T cells are secreting the appropriate interleukins, others form into ________. A) plasma cells B) memory T cells C) memory B cells D) cytotoxic T cells E) suppressor T cells
B) memory t cells
Which of the following conditions will result in a skeletal muscle that produces a greater amount of force? A) more sarcomeres in series B) more sarcomeres in parallel C) fewer myofibrils per muscle cell D) fewer sarcomeres in parallel E) fewer sarcomeres in series
B) more sarcomeres in parallel
People who have type AB blood are considered ________ because they ________. A) universal recipients : have antibodies to A and B B) universal recipients : have no antibodies to A or B C) universal donors : have antibodies to A and B D) universal donors : have no antibodies to A and B E) universalists : cannot receive blood transfusions
B) universal recipients : have no antibodies to A or B
What type of receptor agonists are used to treat people suffering from asthma or nasal congestion?
B2
Which of the following correctly describes cotransport of Y with sodium?
Both Y and sodium move into the cell.
At rest, what is the relative contribution of the sympathetic and parasympathetic nervous systems to the regulation of homeostasis?
Both systems are active but the parasympathetic predominates.
When the body is stressed, what is the relative contribution of the sympathetic and parasympathetic nervous systems to the regulation of homeostasis?
Both systems are active but the sympathetic predominates.
The gray ramus is comprised of what fiber type?
C
What type of gland secretes an acidic oily substance that inhibits bacterial growth?
C Sebaceous glands
Calcitonin is made in the ______
C cells of the thyroid gland
Which of the following is NOT characteristic of rapid eye movement (REM) sleep? A) postural muscles lose tone B) thoughts are illogical and bizarre C) increased parasympathetic activity D) increased brain activity E) decreased limbic system activity
C increased parasympathetic activity
Which of the following is NOT a process whereby calcium is functionally removed from the cytosol of a cell? A) active pumping of calcium across the plasma membrane B) sequestration of calcium by proteins within the cytosol C) active transport of calcium into the smooth endoplasmic reticulum D) sequestration of calcium within the Golgi apparatus E) active transport of calcium into the mitochondria
C) Active transport of calcium into the smooth endoplasmic reticulum
Cells that leave the thymus with the ability to bind to class II major histocompatibility (MHC) molecules will develop into ________. A) cytotoxic T cells B) B cells C) helper T cells D) suppressor T cells E) macrophages
C) Helper T cells
What secretes cytokines that enhance the activity of B cells, cytotoxic T cells, suppressor T cells, and helper T cells? A) Macrophages B) B cells C) Helper T cells D) Cytotoxic T cells E) Suppressor T cell
C) Helper T cells
Which of the antibody classes is able to cross epithelial cells and is therefore present in breast milk? A) IgG only B) IgM only C) IgA only D) both IgG and IgM E) both IgM and IgA
C) IgA only
Which of the following is NOT an accurate description of specific muscle fiber types? A) Fast glycolytic fibers are the largest diameter fibers. B) Slow oxidative fibers are the smallest diameter fibers. C) Slow oxidative fibers are quick to fatigue. D) Fast glycolytic fibers produce their ATP by glycolysis. E) Fast oxidative fibers have a high mitochondrial density.
C) Slow oxidative fibers are quick to fatigue.
The release of ________ by T cells activates natural killer cells in a specific immune response. A) interleukin-6 B) interleukin-1 C) interleukin-2 D) interferon-y E) tumor necrosis factor-
C) interleukin 2
Activation of helper T cell proliferation, once it has bound to its major histocompatibility (MHC) molecule, involves the release of ________ from ________. A) interleukin-10 : macrophages B) interleukin-2 : macrophages C) interleukin-1 : B cells D) interleukin-2 : B cells E) interleukin-4 : cytotoxic T cells
C) interleukin-1: B cells
Once a phagocyte has attached to foreign material, that material is ________. A) degraded externally by enzymes released from a lysosome B) internalized in a lysosome C) internalized in a phagosome D) internalized in a secondary lysosome E) internalized in the Golgi apparatus
C) internalized in a phagosome
During phase 3 of a contractile cell action potential, ________. A) only sodium permeability is increased B) only calcium permeability is increased C) only potassium permeability is increased D) sodium and calcium permeability are both increased E) sodium and potassium permeability are both increased
C) only potassium permeability is increased
In order to be detected by a T cell, the class II major histocompatibility (MHC) molecule of infected cells must go through the process of ________ before presenting the antigen. A) perforin incorporation B) antibody binding C) phagocytosis D) MHC molecule presentation E) complement activation
C) phagocytosis
Activation of a B cell by an antigen results in its proliferation and differentiation into ________, which secrete the antibodies that attack the antigen. A) cytotoxic T cells B) T cells C) plasma cells D) memory cells E) helper T cells
C) plasma cells
What is the polyol associated with glucose? A) aldose B) lactose C) sorbitol D) ascorbic acid E) glycerol
C) sorbitol
The incorporation of perforins into the cell membrane results in the cell s ________. A) being marked for degradation by macrophages B) shrinkage and subsequent death C) swelling and subsequent lysis D) being bound by antibodies E) binding of the helper T cell
C) swelling and subsequent lysis
Once a skeletal muscle cell begins to shorten during an isotonic twitch contraction, ________. A) the amount of force generated by the muscle will continue to increase B) the amount of force generated by the muscle will start to decrease C) the amount of force generated by the muscle will remain constant D) the muscle will continue to shorten until the force generated by the muscle stops increasing E) the muscle will stop shortening once the force is greater than the load
C) the amount of force generated by the muscle will remain constant
People who have type O blood are considered ________ because they ________. A) universal recipients : have no A or B antigens B) universal recipients : have no antibodies to A or B C) universal donors : have no A or B antigens D) universal donors : have no antibodies to A or B E) universalists : cannot receive blood transfusions
C) universal donors : have no A or B antigens
Which of the following is an INCORRECT description of the function of the organelle? A) ATP synthesis occurs in the mitochondria. B) Peptide hormone synthesis occurs in the rough endoplasmic reticulum. C) Breakdown of phagocytosed debris occurs in the peroxisomes. D) Packaging of secretory products into vesicles occurs in the Golgi apparatus. E) Calcium is stored in the smooth endoplasmic reticulum.
C, it occurs it in the lysosomes. A peroxisome is a type of organelle known as a microbody, found in virtually all eukaryotic cells. They are involved in catabolism of very long chain fatty acids, branched chain fatty acids, D-amino acids, and polyamines, reduction of reactive oxygen species - specifically hydrogen peroxide - and biosynthesis of plasmalogens, i.e., ether phospholipids critical for the normal function of mammalian brains and lungs.
Which of the following occurs during accommodation for near vision?
Ciliary muscles contract, causing zonular fibers to become slack, and the lens becomes rounder.
What is the first component of the electron transport chain that accepts electrons from an FADH2 molecule?
Coenzyme Q
A (coenzyme / cofactor) alters the ability of an enzyme to bind its substrate.
Cofactor. (The coenzyme is a particular type of cofactor that does not have any catalytic activity of its own but does participate directly in the reaction catalyzed by its partner enzyme by transferring a chemical group with the substrate.)
Which of the following is a protein found in the body that provides the tensile strength to resist stretching?
Collagen
Which of the following descriptions of collateral ganglia is true?
Collateral ganglia are in the sympathetic nervous system but distinct from the sympathetic chain, and they function as a site of communication between sympathetic preganglionic neurons and postganglionic neurons.
During which of the following steps in cross-bridge cycling in skeletal muscle is ATP bound to myosin: rigor, conformational change in myosin that reduces its affinity for actin, power stroke?
Conformational change in myosin that produces the power stroke.
________ are proteins that form channels between cells, allowing ions and small molecules to diffuse directly from one cell to the other.
Connexins
While contractile proteins are similar in skeletal and smooth muscle cells, the structure and regulation of muscle contraction is quite different. Describe the arrangement of contractile proteins in smooth muscle cells and how contraction is mediated.
Contractile proteins (actin and myosin) are the same in smooth muscle and skeletal muscle. Skeletal muscles are characterized by the repeating arrangement of sarcomeres. In smooth muscle, contractile proteins are oblique to the long axis of the smooth muscle cell. These contractile proteins are attached to the dense bodies where the force generated by the contractile proteins is transmitted to the cell s exterior. Calcium enters the cell through a voltage-sensitive calcium channel to bind with calmodulin. The calcium-calmodulin complex binds to the enzyme myosin light-chain kinase, causing it to become active. The myosin light-chain kinase phosphorylates the myosin light chain, causing it to become active and capable of binding to actin. Thereafter, the cycling of the crossbridges is the same as observed in skeletal muscle. In order to terminate crossbridge cycling, the myosin light chain must be dephosphorylated by a phosphatase enzyme. These enzymes are always active within smooth muscle cells.
17) During skeletal muscle contraction, multiple crossbridge cycles are occurring between the same thick and thin filament. Which of the following best describes this process?
Crossbridge cycling is asynchronous between a certain thick and thin filament.
Which of the following is NOT one of the body s nonspecific defenses against pathogens? A) inflammation B) interferons C) natural killer cell D) cytotoxic T cell E) complement system
Cytotoxic T cell
Which of the following statements about hair cells in the ear is FALSE? A) There are three rows of outer hair cells and one row of inner hair cells. B) Hair cells are surrounded by endolymph. C) Only the inner hair cells of the cochlea function directly in sound transduction. D) Both the hair cells for hearing and those for equilibrium are depolarized when bent toward the kinocilium. E) When potassium channels in hair cells open, potassium ions move into the cell, depolarizing it.
D) Both the hair cells for hearing and those for equilibrium are depolarized when bent toward the kinocilium
What is/are a component of the complement system that coats the bacterial surface, acting as an opsonin to enhance phagocytosis of bacteria. A) CD8 B) CD4 C) Polysaccharides D) C3b E) C2c
D) C3b
The complement cascade can be activated by binding to ________. A) carbohydrates present on bacterial cells only B) antibodies attached to bacterial cells only C) natural killer cells only D) either carbohydrates or antibodies on bacterial cells E) either natural killer cells or carbohydrates on bacterial cells
D) Either carbohydrates of antibodies on bacterial cells
A natural form of passive immunity involves the transfer of ________. A) IgA antibodies across the placenta B) IgE antibodies by sneezing C) IgG antibodies by kissing D) IgA antibodies to an infant through the mother s milk E) IgG antibodies to an infant through the mother's milk
D) IgA antibodies to an infant through the mother's milk
Receptors on every T cell detect foreign antigens on cells of the body by their association with the ________ on the surface of the infected cells of the body. A) membrane attack complex B) CD4 C) CD8 D) major histocompatibility (MHC) molecule E) antibodies
D) Major histocompatibility molecule (MHC)
Each B or T cell has ________. A) one antigen receptor B) two antigen receptors that recognize the same epitope C) two antigen receptors that recognize different epitopes D) many antigen receptors that recognize the same epitope E) many antigen receptors that recognize many epitopes
D) Many antigen receptors that recognize the same epitope
Which of the following statements about the spinothalamic tract is FALSE? A) Pain signals are transmitted along this pathway. B) Cold signals are transmitted along this pathway. C) Warm signals are transmitted along this pathway. D) The pathway crosses to the contralateral side in the brainstem. E) The first-order neuron synapses with the second order neuron in the spinal cord dorsal horn.
D) The pathway crosses to the contralateral side in the brainstem.
In order to be detected by a T cell, the class I major histocompatibility (MHC) molecule of infected cells must go through the process of ________. A) perforin incorporation B) antibody binding C) phagocytosis D) antigen presentation E) complement activation
D) antigen presentation
Diabetes mellitus can be caused by a form of autoimmune disease that attacks ________. A) insulin receptors, preventing insulin from acting on cells B) alpha cells of the pancreas, which destroys insulin production C) GLUT-4 proteins as they insert into the membrane D) beta cells of the pancreas, which destroys insulin production E) the exocrine portion of the pancreas
D) beta cells of the pancreas, which destroys insulin production
Which of the following is an incorrect association between pancreatic cell type and hormone secreted? A) Alpha cells secrete glucagon. B) Beta cells secrete insulin. C) Delta cells secrete somatostatin. D) Epsilon cells secrete calcitonin. E) F cells secrete pancreatic polypeptide
D) delta cells secrete somatostatin
If bacteria are exposed to a B cell in the spleen, they will initiate a(n) ________. A) inflammatory response B) nonspecific immune response C) cell-mediated immune response D) humoral immune response E) response from the complement system
D) humoral immune response
Activation of cytotoxic T cells requires binding to class I MHC molecule complexed with a foreign antigen and the release of ________ from ________. A) interleukin-10 : macrophages B) interleukin-1 : helper T cells C) interleukin-1 : macrophages D) interleukin-2 : helper T cells E) interleukin-2 : macrophages
D) interleukin-2 : helper T cells
Which of the following cells are activated by the release of interleukin-10 from the helper T cells? A) B cells B) natural killer cells C) mast cells D) macrophages E) cytotoxic T cells
D) macrophages
Tissue transplantation has been made possible by our ability to ________. A) inhibit the binding of helper T cells to the HLA B) inhibit interleukin-5 C) alter the expression of the HLA molecules D) match HLA molecules between individuals E) competitively inhibit HLA molecules
D) match HLA molecules between individuals
Natural killer cells can kill infected or abnormal cells by the release of ________, which form pores in the target cell s membrane. A) fragmentins B) interferons C) antibodies D) perforins E) complement proteins
D) perforins
Which of the following chemical messengers is lipophilic? A) glutamate B) histamine C) norepinephrine D) prostaglandin E) gamma-amino butyric acid
D) prostaglandin
A number of tumors and viruses (e.g., Epstein-Barr) are able to escape cytotoxic T cell degradation by inhibiting what? A) the activation of the complement system B) tumor antigen expression C) the production of the class II major histocompatibility (MHC) molecule D) the production of the class I MHC molecule E) helper T cell activation
D) the production of the class I MHC molecule
Which of the following is NOT a function of the initiation factors associated with translation of protein from mRNA? A) They bind to the CAP group at the 5ʹ end. B) They form a complex with small ribosomal subunits. C) They form a complex with charged tRNA. D) They align the first tRNA with the P site on a ribosome. E) They trigger binding of the small ribosomal subunit to AUG.
D, they align with the A site
Active tension
Determined by subtracting the passive tension from the total tension. It represents the active force developed during cross-bridge cycling.
What is the leading cause of amputation in diabetes
Diabetic foot ulcer
Diabetes mellitus is caused by
Disruption of the insulin/GLUT 4 mechanism. In type 1 diabetes, insulin is absent,
80) What hormone released in times of stress directly inhibits the function of the immune system? A) Glucagon B) Aldosterone C) Epinephrine D) ADH E) Corticosteroid
E) Corticosteroid
Which of the following structures is NOT a mechanoreceptor located within the skin? A) Pacinian corpuscles B) hair follicle receptors C) Meissner s corpuscles D) Merkel s disks E) hair cells
E) Hair cells
Which of the following is NOT part of the gate-control theory of pain modulation? A) Inhibitory interneurons can modulate second-order pain neurons. B) Inhibitory interneurons are activated by collaterals of A fibers that are associated with mechanical stimuli. C) Inhibitory interneurons are inhibited by collaterals from the nociceptor afferent. D) A non-painful stimulus can activate the inhibitory interneuron and thereby inhibit the painful stimulus. E) Signals that modify pain originate from higher centers of the brain.
E) Signals that modify pain originate from higher centers of the brain.
Which of the following statements about summation and tetanus is FALSE? A) Summation and tetanus occur at high frequencies of skeletal muscle stimulation. B) Summation and tetanus do NOT occur in cardiac muscle. C) Summation and tetanus result from increases in cytosolic calcium levels. D) Summation and tetanus result in greater tension in the muscle. E) The maximum tension developed during summation and tetanus is treppe.
E) The maximum tension developed during summation and tetanus is treppe
Which of the following statements about the plateau phase of a contractile cell action potential is FALSE? A) Calcium permeability is high relative to the resting state. B) Sodium channels are inactivated. C) Potassium permeability is low relative to the resting state. D) The cardiac muscle is in the absolute refractory period. E) The membrane potential remains the same as the peak of the action potential for about 200 milliseconds.
E) The membrane potential remains the same as the peak of the action potential for about 200 milliseconds.
Which of the following is NOT an action of interleukins released by phagocytic cells? A) increasing endothelial cell synthesis of adhesion molecules B) stimulation of the release of neutrophils from bone marrow C) acting as endogenous pyrogens to increase body temperature D) stimulating the production of acute phase proteins from the liver E) acting as opsonins to facilitate phagocytosis
E) acting as opsonins to facilitate phagocytosis
Once IgM antibodies have bound to antigens, they are removed by ________. A) activating the alternate pathway of the complement system B) opsonizing the antigen, making it more susceptible to phagocytosis C) enhancing natural killer cell activity D) binding to mast cells to stimulate secretion of histamine E) activating the classical pathway of the complement system
E) activating the classical pathway of the complement system
All the messengers function as hormones for which of the following chemical classes? A) amines B) peptides/proteins C) steroids D) eicosanoids E) amino acids
E) amino acids
Which type of T cell has antigen receptors? A) cytotoxic T cells only B) suppressor T cells only C) helper T cells only D) both cytotoxic and helper T cells E) cytotoxic, helper, and suppressor T cells
E) cytotoxic, helper, and suppressor T cells
17) Which of the following hormones is NOT secreted by the endocrine region of the pancreas? A) insulin B) glucagon C) somatostatin D) pancreatic polypeptide E) glucocorticoids
E) glucocorticoids
What cells are also called CD4 cells? A) B cells B) plasma cells C) cytotoxic T cells D) suppressor T cells E) helper T cells
E) helper T cells
The tension produced during skeletal muscle contraction can be increased by all of the following except one. Which one is it? A) recruiting motor units B) increasing the frequency of action potentials in the motor neuron innervating the muscle C) increasing the frequency of action potentials in the muscle fiber D) initiating the contraction when the muscle is at its optimum length E) increasing the load on the muscle
E) increasing the load on the muscle
The development of memory B cells in response to an antigen requires the secretion of ________ from ________ cells. A) interferon- y: cytotoxic T cells B) tumor necrosis factor- a: natural killer cells C) interleukin-6: helper T cells D) interleukin-1: cytotoxic T cells E) interleukin-2: helper T cells
E) interleukin-2: helper T cells
Which of the following steps initiates an inflammatory response? A) Arterioles dilate. B) Capillary permeability increases. C) Leukocytes migrate to the infection. D) Macrophages secrete cytokines. E) Macrophages engulf the debris or foreign material.
E) macrophages engulf the debris or foreign material
The primary mechanism whereby cytotoxic T cells are able to destroy infected cells involves ________. A) enzymatic degradation B) incorporation of the major attack complex C) phagocytosis D) activation of the complement system E) the incorporation of perforins into the cell membrane
E) the incorpoation of perforins into the cell membrane
The antigen-binding region of an antibody is formed by the ________. A) constant region composed of two light chains B) constant region composed of a heavy chain and a light chain C) variable region composed of two light chains D) variable region composed of two heavy chains E) variable region composed of a heavy chain and a light chain
E) variable region composed of a heavy chain and a light chain
Compared to humoral immunity, cell-mediated immunity is more likely to defend against which of the following? A) virally-infected cells only B) transplanted tissue only C) cancer cells only D) both virally-infected cells and cancer cells E) virally-infected cells, cancer cells, and transplanted tissue
E) virally-infected cells, cancer cells, and transplanted tissue
____________ are modified fatty acids that function in intercellular communication and include prostaglandins and thromboxanes.
Eicosanoids
What is a general name for the non-cellular material that holds the widely scattered cells of connective tissue together?
Elastin
What is the graded change in membrane potential that occurs at the motor end plate of skeletal muscle called?
End-plate potential
Energy in the form of ATP is essential to the contractile process. Describe the cellular sources of energy for skeletal muscle fibers and how those energy sources play a role maintaining muscle activity at low- and high-intensities of activity.
Energy in the form of ATP is required for the release of the actin-myosin complex, in addition to energizing the myosin head. Thus, in order for skeletal muscle to contract, there must be an adequate supply of energy. At rest, the concentration of ATP is relatively low. In order to prevent this ATP supply from being depleted during the first few seconds of muscle contraction, creatine phosphate is present to act as an energy buffer by providing the Pi necessary to re-energize the ATP and allows crossbridge cycling to continue to break the actin-myosin complexes. Creatine phosphate is in equilibrium with creatine, whose concentration is also limited within skeletal muscle. The muscle must then switch to metabolizing glucose from its storage as glycogen in the muscle or liver (glucose must travel through the blood in order to enter the muscle). If the intensity of exercise is maintained at moderate levels or below, the aerobic metabolism of fatty acids through oxidative metabolism will take over as the primary source of energy. The fatty acids provide substrate (acetyl CoA) for the Krebs cycle and the electron transport chain as long as enough oxygen is present to act as the final accepter of electrons. However, if exercise intensity increases further, the ability of aerobic metabolism to supply energy can be compromised by the limitations on blood flow (oxygen delivery) to the active muscle. In that case, oxygen delivery would be compromised and substrate-level metabolism would have to take over the production of ATP. The byproduct of this substrate-level metabolism is lactic acid, whose dissociated hydrogen ion can limit the ability of the muscle to generate force through a number of mechanisms.
What are phagocytic leukocytes that attack parasitic cells by releasing toxic molecules once they have attached themselves to the parasite?
Eosinophils
What tissue type functions in the transport of specific molecules from one body compartment to another?
Epithelial
________ carry/carries oxygen to the cells of the body, while the synthesis of these cells is regulated by the hormone ________.
Erythrocytes, erythropoeitin
T/F G and C are held together by 2 H bonds
F
T/F an anticodon is complementary to the triplet coding for a particular amino acid.
F
The hypothalamus is connected to the posterior pituitary by the hypothalamic-pituitary portal system.
F, anterior pituitary
T/F ) Binding of a ligand to the a1-adrenergic receptor activates Gi, thereby inhibiting the synthesis of cAMP.
False
T/F A decrease in the amplitude of a receptor potential over time in the presence of a continued stimulus is called habituation.
False
T/F A motor unit consists of a skeletal muscle fiber (cell) and all of the motor neurons that innervate that skeletal muscle fiber.
False
T/F A skeletal muscle cell produces force for only a small portion of its contractile cycle because only a small portion of the crossbridge cycle involves force generation.
False
T/F A skeletal muscle with slower ATPase activity can complete more crossbridge cycles per second.
False
T/F All autonomic nerves contain only efferent fibers.
False
T/F Although pain perception can vary between individuals, one person always perceives the identical painful stimulus as being the same.
False
T/F Antigens that evoke the production of both plasma cells and memory B cells are T-independent antigens.
False
T/F As skeletal muscle shortens with contraction, the length of the I band remains constant as the length of the A band decreases.
False
T/F Binding of ATP to myosin increases myosin s affinity for actin.
False
T/F C-reactive protein is an acute phase protein released by neutrophils that acts as an opsonin when bound to bacteria.
False
T/F Capsaicin causes a burning sensation in the mouth because it binds to TRPV1 receptors.
False
T/F Cell-mediated immunity involves the actions of the B cells, whereas humoral immunity involves the actions of T cells.
False
T/F Chemical nociceptors respond to chemical substances released by damaged tissue.
False
T/F Cytotoxic T cells are also called CD4 cells.
False
T/F Cytotoxic T cells can mount an immune response more quickly than natural killer cells.
False
T/F Diabetes mellitus type 1 is a genetic disorder that affects the genes for insulin synthesis.
False
T/F Each semicircular canal can only detect rotation in one direction.
False
T/F Each taste receptor cell is specific to only one of the four primary tastes.
False
T/F Extensive convergence exists from the cones to the bipolar cells within the fovea.
False
T/F Helper T cells are able to directly kill any cell that they come into contact with.
False
T/F Hemoglobin in skeletal muscle acts as an oxygen buffer.
False
T/F In a neural pathway, when an excitatory synapse follows an inhibitory synapse, this is called disinhibition.
False
T/F Intrafusal muscle fibers contribute directly to the tension produced during muscle contraction.
False
T/F Macrophages release bradykinin during inflammation, causing the sensation of pain.
False
T/F Olfactory receptors are tonic (slowly adapting) receptors that detect odors.
False
T/F Slow-wave potentials are caused by cyclical fluctuations in opening and closing of potassium channels.
False
T/F Taste receptor cells are located only on the tongue.
False
T/F The constant region of an antibody determines its specificity, whereas the variable region determines its mechanism of action.
False
T/F The contraction phase of a twitch lasts longer than the relaxation phase.
False
T/F The diabetes epidemic is due to increases in diabetes mellitus 2 only; there has been no significant increase in diabetes mellitus type 1.
False
T/F The membrane attack complex is formed by major histocompatibility proteins.
False
T/F The mitotic spindle forms from the centrosome during cell division.
False
T/F The primary hormone released from the adrenal medulla is norepinephrine.
False
T/F The somatic nervous system provides both excitatory and inhibitory signals to skeletal muscle.
False
T/F The structure of the antigen receptor on the T cell is determined after the cell is exposed to a pathogen.
False
T/F Thick filaments have many protrusions along their middle (head of the myosin filaments) but none at their ends.
False
T/F Tonic receptors are best at detecting changes in the environment.
False
T/F bone marrow is considered a peripheral lymphoid tissue
False
T/F Diabetic ketoacidosis is more common in diabetes mellitus type 2
False because circulating blood glucose is enough to prevent this
T/F Atropine, first derived from the Atropa belladonna plant, is a nicotinic receptor antagonist.
False, it is a muscarinic antagonist
T/F Diabetes mellitus types 1 and 2 are both associated with increased body weigh
False, only type 2
Force development by muscle cells requires an interaction between actin and myosin. Describe the proteins involved in the development of force through the process of the sliding-filament theory, including crossbridge cycling.
Force development in skeletal muscle requires the interaction between the head of the myosin molecule (crossbridge) and actin. The head of the myosin molecule contains two important regions: 1) an actin-binding site, and 2) an ATPase that derives energy from ATP for force development. Actin monomers are arranged into two filaments (thin filaments) that are twisted into a double helix and are anchored to the Z -line. Myosin molecules are arranged side by side out of phase with one another. At the same time, myosin dimers are bound tail to tail such that the myosin heads on either side of the thick filament pull toward one another. The muscle is able to generate force by the cycling of crossbridges that bind to actin. The cycling starts with an ATP molecule binding to the ATPase portion of the myosin head that is still bound to actin and is in the low-energy form. This ATP binding initiates a conformational change that removes actin. The ATP molecule is then split into ADP and Pi, changing the myosin head into a high-energy form (cocked). Once this energized myosin head comes in contact with an actin molecule whose binding site is exposed, the myosin will bind to the actin molecule. The release of Pi allows the myosin head to return to the low-energy form, and in the process, the myosin head pivots, pulling the Z lines of the sarcomere toward one another. The bond between actin and myosin is maintained until ATP is able to bind to the myosin head. In the absence of ATP, the muscle is maintained in the state of rigor. The cycling of crossbridges causes the two thin filaments of the sarcomere to be pulled toward one another by the thick filament, thereby pulling the Z-lines closer together.
Which of the following correctly describes a pathway for secretion of a hormone under the control of tropic hormones?
GHRH stimulates GH release, which stimulates insulin-like growth factor release.
What type of glucose transporter is located in the endothelial cells of the blood-brain barrier?
GLUT 1
In the B-islet cells of the pancreas, _________ and ________ serve as the glucose sensor for insulin release
GLUT 2, glucokinase
Insulin triggers the insert ion of what protein into the cell membrane of its target cell?
GLUT 4
The layer of carbohydrates on the external surface of a cell is called what?
Glycocalyx
ATP is synthesized by substrate-level phosphorylation during which of the following?
Glycolysis and krebs cycle only. NOT during the conversion of pyruvate to lactate
Which tropic hormone is responsible for controlling the release of follicle stimulating hormone from the anterior pituitary?
GnRH
The detection of odorants occurs via the binding of organic molecules to receptors on the cell membrane, activating ________ that ultimately causes the ________.
Golf : cation channel to open
The region of thick filaments that has no overlap with thin filaments.
H zone
Blood levels of what form of lipoproteins are decreased by diabetes mellitus?
HDL
Describe humoral immunity, including the details about the different classes of antibodies that mediate this immunity.
Humoral immunity involves the release of antibodies from B cells once they are exposed to specific antigens. When a B cell binds directly to a T-independent antigen (typically a bacterial polysaccharide), the B cell is stimulated to proliferate and differentiates into plasma cells exclusively (B cell effectors). The polysaccharide provides a strong enough signal to initiate proliferation in the absence of interleukin-2, which is necessary to stimulate proliferating cells to differentiate into memory cells. The plasma cells secrete antibodies (2000 per second). These antibodies circulate in the blood for several weeks, binding to the antigens that originated their production. However, since no memory cells are generated in the absence of interleukin-2, repeated exposure will initiate a primary immune response (no secondary immune response). Helper T cells release the interleukin-2 that stimulates the proliferation and differentiation of B cells into plasma and memory cells. In the presence of a T-dependent antigen, a B cell binds to the antigen and presents a class II major histocompatibility (MHC) molecule to the helper T cell. When a helper T cell binds to the class II MHC molecule, it induces the secretion of interleukin-2 from the helper T cell. Interleukin-1 from the the B-cell acts to stimulate the proliferation of the helper T cell. There are five classes of antibodies (IgM, IgD, IgE, IgG, and IgA) that differ in the structure of their heavy chains. Antibodies do not directly kill pathogenic cells. However, all antibodies have the ability to neutralize an antigen s activity by binding to it and blocking access. In addition, all antibodies can cause agglutination, since each antibody has the potential to bind to two separate pathogenic cells. Once bound, the IgG and IgM antibodies can be opsonized, rendering the cell more susceptible to phagocytosis. The IgG antibody can also kill its target cells by activating the complement system or natural killer cells. IgM is one of the more common antibodies that produces the primary antigen response. IgD acts as an antigen receptor on B cells. IgG is another of the common classes of antibodies that produces secondary responses and can cross the placenta. IgE is involved in allergies and hay fever. Finally, IgA crosses epithelial cells and is therefore present on mucosal surfaces and in breast milk.
How does hyperglycemia cause ketoacidosis?
Hyperglycemia causes dehydration, which leads to a drop in blood pressure reflexively activating the sympathetic nervous system including the release of epinephrine from the adrenal medulla. Epinephrine mobilizes energy stores in several ways, including promoting lipolysis in adipose tissue thereby increasing blood levels of free fatty acids. These fatty acids can be taken up by the liver for beta oxidation, which leads to the production of ketones. Because ketones are an acid, ketoacidosis has occurred.
Appears as light bands under the microscope.
I band
What portion of a sarcomere shows up as light striations when viewed under a microscope?
I band
Secreted in breast milk, this class of antibody helps protect the newborn through neutralization and agglutination of antigen.
IgA
This class of antibody functions through neutralization and agglutination of antigen, but cannot cross epithelial cells. It is also an antigen receptor on B cells.
IgD
During allergic reactions, this class of antibody causes mast cells and basophils to release histamine.
IgE
What antibody is most involved in the allergic response? A) IgG B) IgM C) IgA D) IgD E) IgE
IgE
The most abundant class of antibody in the body, this antibody can function by neutralization, agglutination, opsonization, complement activation, and enhancement of natural killer cell activity.
IgG
This antibody class is the most common class of antibody produced in the primary response to an antigen. It acts through neutralization, agglutination, and activation of the complement system
IgM
Characterize the three types of immunities and the mechanisms that underlie allergic responses.
Immunization refers to exposure to a safe form of microorganism that is not expected to cause disease, but will stimulate the body to mount an immune response. The exposure initiates a primary immune response and produces memory cells such that, if the person is ever exposed to the infection again, the body will be able to mount a rapid and strong secondary immune response to the pathogen. Active immunity can be either artificial (as described above) or natural (previous exposure to the pathogen). Another form of immunity is passive immunity, where antibodies to a particular pathogen are injected into a person. Some disease occurs so rapidly that we are not able to mount an immune response in enough time to survive. Thus, injection of antibodies can fight the disease. However, these antibodies only remain in the body for a relatively short time and, because no memory cells are generated, there will not be a secondary response when exposed a second time. Passive immunity normally occurs in fetuses and babies. Maternal IgG crosses the placenta and provides passive immunity for the fetus, while the IgA present in the early breast milk (colostrum) will provide protection to the newborn for weeks to months. Allergies are exaggerated reactions to environmental antigens that usually involve IgE antibodies. Excessive IgE release in response to pollen causes the tail of the IgE to bind with mast cells. When the IgE binds to pollen, the mast cells they are attached to are stimulated to degranulate and release histamine. Runny nose and sneezing are reflections of the inflammatory response (vasodilation and increased capillary permeability) in the respiratory tract. Anaphylactic shock is a life-threatening form of allergy, where the degranulation of mast cells is so widespread that the vasodilation causes a drop in peripheral resistance and thereby mean arterial pressure.
SWS characteristics
In SWS, muscle tone is decreased, but occasional bursts of involuntary activity occur every 10-20 minutes. In the brain, activity decreases in most regions except the parasympathetic nervous system, where activity is increased. During SWS, a person may dream but the dreams are less detailed than during REM sleep, and are more logical and less emotional. In REM sleep, postural muscles lose their tone and become paralyzed and the jaw muscles relaxed (causing the mouth to open). Snoring usually occurs within SWS sleep.
Mobitz type 2 heart block
In second-degree Mobitz type II heart block, some of the electrical signals don't reach the ventricles. However, the pattern is less regular than it is in Mobitz type I. Some signals move between the atria and ventricles normally, while others are blocked. On an EKG, the QRS wave follows the P wave at a normal speed. Sometimes, though, the QRS wave is missing (when a signal is blocked). Mobitz type II is less common than type I, but it's usually more severe. Some people who have type II need medical devices called pacemakers to maintain their heart rates.
Describe the anatomical arrangement of the somatic nervous system, including the concept of motor units.
In the somatic nervous system, a single efferent neuron runs from the central nervous system to the skeletal muscle. These motor neurons originate in the ventral horn of the spinal cord and receive input from multiple sources, including afferent neurons. A single motor neuron innervates multiple muscle fibers but each muscle is innervated by a single neuron. A motor unit describes a single motor neuron and all of the skeletal muscle fibers innervated by that neuron. Thus, when a motor neuron is activated, all of the muscle fibers innervated by that motor neuron are stimulated to contract simultaneously.
Which of the following is NOT one of the four steps involved in phagocytosis? A) attachment B) internalization C) degradation D) exocytosis E) interleukin release
Interleukin release
Keratin is an example of which type of cytoskeletal protein? A) microfilaments B) intermediate filaments C) microtubules D) centrioles E) tight junctions
Intermediate filaments
The fluid compartment with a high sodium concentration that contains only trace amounts of protein is called
Interstitial fluid
how does glucose enter the brain
It is pumped in by an active transport system
How does latroxin, the venom of the black widow spider, cause muscle spasms and rigidity.
It stimulates acetylcholine release from motor neurons.
What are the cones called that respond to the red spectrum of light?
L cones
Which of the following is NOT a monosaccharide? A) glucose B) fructose C) galactose D) deoxyribose E) lactose
Lactose
What is the region of the striated muscle s banding patterns that contains only the connections between the tails of myosin molecules ?
M line
Which cytoskeletal proteins provide the structural support for microvilli? A) microfilaments B) intermediate filaments C) microtubules D) centrioles E) tight junctions
Microfilaments
Irrespective of an individual muscle cell s ability to regulate the amount of force developed by that cell, the force generated by a skeletal muscle is also controlled at the whole muscle level. Describe the mechanism whereby force of a whole muscle can be modified, including a discussion on motor units.
Muscles that are involved in fine movement will have fewer muscle cells per motor unit than muscles involved in more gross movement. there is a correspondence between the size of motor units activated and their order of recruitment. The physiological determinant of which motor units are activated is the sensitivity of the motor neurons to action potential frequency; smaller motor neurons are stimulated to generate an action potential at a lower frequency of action potentials than larger diameter motor neurons. The smaller motor units are innervated by smaller diameter motor neurons. creased, the frequency of the action potentials from the motor center is increased, thereby recruiting more of the larger fibers that are capable of generating greater force.
Compare and contrast AMPA and NMDA
NMDA receptors initiate the opening of calcium channels, whereas AMPA receptors cause sodium channels to open. When glutamate is released into the synapse, both receptors are activated. Even though the NMDA channels are open, the movement of calcium through these channels is blocked by magnesium. However, if the frequency of action potentials is increased, large amounts of glutamate are released. This produces a stronger depolarization that prevents the magnesium-induced blockade of the NMDA, thereby increasing the extent of depolarization. At the same time, this increased calcium influx triggers the activation of protein kinases. These protein kinases can 1) phosphorylate AMPA receptors, making them more sensitive to glutamate (which further enhances the depolarization), and 2) stimulate the postsynaptic membrane to release a paracrine messenger that triggers pre-synaptic release of glutamate.
Identify the branches of the peripheral nervous system for which norepinephrine is the neurotransmitter and describe the receptors responsible for responding to norepinephrine. Include the mechanisms whereby these receptors transduce the response to norepinephrine.
Neurons that release norepinephrine are referred to as adrenergic neurons. Norepinephrine is the neurotransmitter for most postganglionic sympathetic neurons (except sympathetic neurons that innervate sweat glands). The end organ receptors for norepinephrine are classified into two majors groups: and receptors. Within each of these classes are several subclasses of receptors with different sensitivities to catecholmines (norepinephrine and epinephrine) and different links to second messenger cascades. Each of the adrenergic receptors are metabotropic and are coupled to a G protein, but the particular G protein can be different (Gs vs Gi). The 1 adrenergic receptor subtype is coupled to activation of phospholipase C for the synthesis of inositol triphosphate, while the 2 adrenergic receptor subtype acts through Gi to suppress the synthesis of cAMP. All three of the receptors are stimulatory, linked through Gs, and are involved in the activation of cAMP.
Describe the effects of neuropathy of the autonomic nervous system.
Neuropathy can have a wide range of effects on the autonomic nervous system, thus producing a wide variety of symptoms. Neuropathy of cardiac nerves can lead to arrhythmias. Neuropathy of renal nerves can lead to incontinence or hypotension. Neuropathy of nerves to the gastrointestinal tract can cause a decrease in muscle tone anywhere along the tract and it can decrease appetite. Neuropathy of nerves to the reproductive system can cause erectile dysfunction, impotence or decreased sexual arousal. In addition to these specific neuropathies, loss of autonomic function to various internal organs also impairs thermoregulation and the ability of the body to adapt to stressors including exercise.
Training induces a number of changes within skeletal muscle that are specific to the type of training employed. Describe the changes that occur in skeletal muscle in response to training.
One reason why athletes train is to increase the capacity of their muscles to perform the work that their sport requires. Athletic training can be broken into two basic types: aerobic and anaerobic, depending upon the energy systems that are stressed by the specific training modality. In response to aerobic training, some of the fast glycolytic fibers are converted into fast oxidative fibers. This is accompanied by an increased mitochondrial density (size and number), an increase in the number of capillaries that surround each muscle fiber, and a decrease in the diameter of the muscle fiber (the last two would facilitate the delivery of oxygen to the active muscle fibers). For the slow oxidative fibers, they do not appear to be capable of converting to fast fiber types. However, the changes in the slow oxidative fibers to aerobic training would be similar to the fast oxidative fibers. In contrast, high-intensity anaerobic exercise will increase the glycolytic capacity of the muscle fibers (switch some of the fast oxidative to fast glycolytic fibers). At the same time, the density of mitochondria (size and number) will be decreased, the concentration of glycolytic enzymes will be increased, and the diameter of the muscle fibers will be increased. The increased skeletal muscle girth in an individual who regularly weight trains is related to an increase in the diameter of muscle fibers (increased myofibrils) rather than an increase in the number of muscle fibers.
What is the main ionotropic purinergic receptor that binds ATP?
P2X
What is the main GPCR that binds ATP?
P2Y
Which of the sensory receptors located within the skin are located deep within the dermis?
Pacinian corpuscles and Ruffini s endings
Identify the branches of the peripheral nervous system for which acetylcholine is the neurotransmitter and describe the receptors responsible for responding to acetylcholine. Include the mechanisms whereby these receptors transduce the response to acetylcholine.
Peripheral neurons that release the neurotransmitter acetylcholine are classified as cholinergic. Acetylcholine is released by all autonomic preganglionic fibers, postganglionic fibers of the parasympathetic nervous system, and the somatic branch of the efferent nervous system. One exception is that acetylcholine is a postganglionic sympathetic neurotransmitter for sweat glands. The two classes of cholinergic receptors are termed nicotinic (based upon the binding of this receptor to nicotine) and muscarinic (based upon the binding of this receptor to a toxic chemical in mushrooms). Nicotinic receptors are ionotropic receptors (receptor and ion channel are within the same protein) that are always excitatory. Thus, the binding of acetylcholine increases the number of open non-selective cation channels that are permeable to both sodium and potassium. The greater electrochemical gradient for sodium means that activating a nicotinic receptor will result in a depolarization of the membrane (i.e., more sodium moves in than potassium moves out). Nicotinic receptors are found on all autonomic postganglionic fibers and the end organ of the somatic nervous system (skeletal muscle). Muscarinic receptors are coupled to G proteins. Thus, these metabotropic receptors can be either inhibitory or excitatory, depending upon the target cell and the signal transduction pathway. Muscarinic receptors are found on the effector organs of the parasympathetic nervous system.
Which of the following is TRUE of photoreceptors in the light (relative to the dark)?
Phosphodiesterase is more active.
In order to synthesize eicosanoids, ________ catalyzes the release of ________ from a membrane phospholipid.
Phospholipase 2, arachidonic acid
The fluid compartment with a high sodium and protein concentration is called ________.
Plasma
Describe the process whereby a polypeptide chain, which has been translated in the rough endoplasmic reticulum, is converted to an active protein hormone.
Polypeptide made in RER (prepropeptide) --> propeptide --> SER --> transport vesicles --> Golgi --> vesicles --> release. Peptides are cleaved in Golgi & transport vesicles to make it biologically active. Peptide fragments that were cleaved are also released (may or may not be biologically active).
Which of the following descriptions is TRUE for the parasympathetic nervous system, but NOT the sympathetic nervous system?
Postganglionic fibers release acetylcholine.
Which of the following is FALSE of sympathetic activity to the SA node? A) Norepinephrine binds to beta1 adrenergic receptors. B) cAMP levels in the pacemaker cells increases. C) Funny channel opening is enhanced. D) The rate of spontaneous depolarization is increased. E) Potassium channel closing is enhanced.
Potassium channel closing is enhanced.
Describe the anatomy of the parasympathetic nervous system and how that differs from the sympathetic nervous system.
Preganglionic neurons from the parasympathetic nervous system originate from the brainstem and the sacral region of the spinal cord (craniosacral region). The parasympathetic nerves that leave the spinal cord do not join with the spinal nerve as occurs in the sympathetic nervous system. Instead, they join with other parasympathetic preganglionic fibers to form pelvic nerves. Generally speaking, preganglionic parasympathetic nerves are long (compared with the postganglionic nerves), traveling to a ganglion that is located near the effector organ. This arrangement is quite different from the sympathetic nervous system, where most preganglionic nerves are short and enter ganglia within the sympathetic trunk. Thus, the parasympathetic nervous system is able to exert more discrete effects than the sympathetic nervous system due to the lack of interconnection between ganglia. Four parasympathetic preganglionic neurons originate from cranial nerve nuclei located within the brainstem, which explains why some preganglionic parasympathetic nerves travel within cranial nerves. The vagus nerve (X) is one of the more important parasympathetic nerves, innervating the lungs, heart, stomach, etc. The other cranial nerves that contain preganglionic parasympathetic axons are the oculomotor (III), facial (VII), and glossopharyngeal nerves (IX).
GLUT 4
Primarily expressed on muscle cells and adipocytes. In contrast to the other 4 glucose transporters, it is the major transporter that is responsive to insulin (unregulated with higher insulin levels). Insulin --> greater NUMBER OF GLUT 4 receptors
Which of the following components of an ECG represents ventricular depolarization?
QRS complex
elevated arousal threshold occurs in
REM only
What are the two major regions of the heart containing pacemaker cells?
SA node and AV node
Which of the following is the correct conduction pathway through the heart?
SA node; AV node; bundle of His; bundle branches; Purkinje fibers
Where are triglycerides synthesized
SER
Where is calcium primarily stored
SER
he membrane of the rough endoplasmic reticulum is continuous with what other membrane(s)?
SER and nuclear envelope
What are the components of sound that are detected within the ear and how does that sound reach the inner ear where it is transduced into electrical energy?
Sound waves travel and affect the gas molecules that compose the air by putting them into motion. Sound waves traveling through the air consist of regions where the air molecules are closer together (compressed) and regions where those molecules are further apart (rarified). The amplitude of sound is proportional to the differences in air molecule densities between the compressed and rarified air. Amplitude is expressed as a log scale in decibels. The pitch of the sound is determined by the frequency of the sound waves measured as the number of waves per second (hertz: Hz). To detect sound, the properties of the sound wave must be transmitted to a solid structure. That transition occurs at the ear drum where sound waves cause the tympanic membrane to vibrate at the frequency of the sound waves. That vibration is passed along the middle ear across three bones: from the malleus (hammer), to the incus (anvil), and finally, onto the stapes (stirrup). The stapes is in contact with the cochlea at the oval window. Once the vibration reaches the stapes, it is passed to the oval window, which vibrates the fluid of the cochlea. There are two membranes within the cochlea (basilar and vestibular) that separate the cochlea into three fluid filled compartments (scala vestibuli, scala tympani, and scala media). The tympani and vestibuli are filled with perilymph while the media is filled with endolymph. Vibration is passed from the oval window to the scala vestibuli onto the scala tympani. This will cause the basilar and vestibular membranes to vibrate as well. The organ of Corti, which contains the hair cells that detect sound, is located on the top of the basilar membrane. The stereocilia of the hair cells are embedded within the tectorial membrane. When the basilar membrane vibrates, the stereocilia that are attached to the tectorial membrane are sheared. This movement bends the stereocilia, causing a change in membrane potential within the hair cell.
Along with nonspecific immunity is specific immunity, which is targeted at particular pathogens. Describe the general features of the specific immune response.
Specific immune responses are directed toward particular pathogens through the actions of B cells and T cells. B cells secrete antibodies that are part of the humoral immunity, while T cells constitute the cell-mediated immunity. B cells have no direct effect on pathogens, except through the release of antibodies, whereas T cells affect pathogens directly. B and T cells bind to antigens, complex membrane proteins, or carbohydrates on the pathogens. Each antigen has a unique site (epitope) that is targeted by a specific B or T cell. These cells contain antigen receptors on their surface that bind to particular antigens. The antigen receptor on a B cell is similar in structure to an antibody s. Antibodies (immunoglobulins) are composed of heavy and light chains arranged in a Y shape. The chains are bound by disulfide bridges. The two ends are the variable regions containing the antigen binding sites. The T cell antigen receptor is in the same family as the B cell membrane antibody, but is different in structure. Each B and T cell expresses thousands of antigen receptors on its surface (all similar to one another) that allows it to detect very low concentrations of pathogens. The specific antigen receptor is determined by a random series of genetic events in the development of the cell, leaving each cell with a unique antigen receptor. Thus, the body has millions of different receptors in order to respond to the multitude of pathogens to which it is exposed. When a pathogen first invades the body, at least one of the millions of different B or T cell antigenic receptors will bind to that pathogen. This initiates a clonal selection where the activated lymphocyte is stimulated to proliferate into effector cells (that either produce antibodies or attack the cell) and memory cells (which facilitate responses to this pathogen in the future). The effector cells are lost days after they are produced, whereas memory cells remain in the body. The process outlined above is referred to as a primary immune response. This response is the first to a particular pathogen, which requires 10-17 days to be activated, and the number of effector cells (T cells) and the amount of antibodies (B cells) produced are quite low. Upon subsequent exposures, specific memory cells initiate the secondary immune response. The response peaks in 2-7 days and produces much greater concentrations of plasma cells and antibodies. However, one might wonder why one of those millions of antigenic receptors is not specific for the body in which they reside. As B and T cells mature, they are screened for reactions to self. Those that respond to self are destroyed by apoptosis.
1,3-bisphosphoglycerate
Substrate-level phosphorylation, generates ATP, converted from Glyceraldehyde 3 phosphate
(T/F) Connexons are a necessary part of the synapse
T
(T/F) Eicosanoids are released immediately upon synthesis.
T
(T/F) Initiation of a withdrawal reflex also activates the crossed-extensor reflex.
T
(T/F) Thyroid hormones alter the transcription of mRNA in the target cell
T
(T/F) Tyrosine kinases are enzymes that add a phosphate group to tyrosine residues on other proteins, changing the conformation of those proteins.
T
Hormones transported in blood bound to proteins are metabolized more slowly than those traveling dissolved in plasma. (T/F)
T
T/F All spinal nerves are mixed nerves containing both sensory and motor fibers.
T
T/F astrocytes provide support for the developing blood brain barrier
T
T/F there is no phase where all valves are open or all valves are closed
T
Which of the following components of an ECG represents ventricular repolarization?
T wave
The release of LH and FSH by the anterior pituitary is under control of the same hypothalamic tropic hormone.
T. GnRH
Describe the general structure of the sympathetic nervous system, including the three anatomical configurations and how they contribute to the overall sympathetic response.
The efferent pathway of the sympathetic nervous system is composed of two neurons, connected in series, that provide for communication between the central nervous system and the effector organ. Those neurons communicate with one another by synapsing within autonomic ganglia. The neurons that travel from the central nervous system to the sympathetic ganglia are the preganglionic neurons, while those that travel from the ganglia to the effector organ are the postganglionic neurons. The preganglionic neurons of the sympathetic nervous system emerge from the lateral horn of the spinal cord within the thoracic and lumbar (thoracolumbar) regions, and exit from the ventral root. The dorsal and ventral roots combine to form the spinal nerve. Thereafter, the organization of the sympathetic nervous system can be described in three ways, based upon anatomical differences. First, the most common arrangement involves a short preganglionic neuron (compared to the postganglionic neuron) that leaves the spinal nerve via a branch called the white ramus and enters one of several sympathetic ganglia. These ganglia are linked together to form a structure that parallels the spinal cord within the sympathetic chain. After entering the sympathetic chain, a preganglionic neuron may branch into several collateral axons that travel up and down the sympathetic trunk to synapse with other postganglionic neurons. Each of these postganglionic neurons travels to a particular effector organ. Thus, activation of the sympathetic nervous system typically produces a response that is widespread, affecting multiple organs simultaneously. The second anatomical arrangement of the sympathetic nervous system contains a long preganglionic fiber that innervates the adrenal medulla. In this case, the chromaffin cells of the adrenal medulla act as the postganglionic neuron. When stimulated, chromaffin cells release catecholamines into the blood (80% epinephrine, 20% norepinephrine, and trace amount of dopamine). This architecture reinforces the widespread effect of the sympathetic nervous system on the body. The final anatomical arrangement contains preganglionic neurons that synapse with postganglionic fibers in collateral ganglia located outside of the sympathetic trunk. One example is a ganglion within the digestive system called the celiac ganglion, which is innervated by a long preganglionic neuron and is located outside of the sympathetic trunk. This arrangement provides for some very specific activity particular to organs, although this type of arrangement is uncommon.
Which of the following statements is TRUE of communication across the neuromuscular junction?
The end-plate potential is always of sufficient magnitude to depolarize the muscle cell to threshold to initiate an action potential.
How is the intensity of a stimulus encoded during information transmittal to the central nervous system?
The frequency of action potentials transmitted to the central nervous system is greater for a stronger stimulus.
The response of every sensory receptor is governed by the law of specific nerve energies. Explain this law and its consequence for a receptor's response to low- and high-intensity stimuli, along with the general process of sensory transduction.
The law of specific nerve energies states that a given sensory receptor is specific for a particular energy modality. Thus, different modalities of energy, including light waves, sound waves, pressure, temperature, etc., are ultimately transduced into electrical energy in the form of an action potential. The specific energy modality to which a receptor responds best (low energy state) is called the adequate stimulus. Receptors will also respond to other energy forms, but they must be at a higher energy to activate that receptor. However, our perception of a stimulus is linked to the receptor that has been activated. Thus, activating a photoreceptor on the retina by pushing on the eye (pressure) will result in our perception of a flash of light even though the stimulus was pressure. The process of converting one form of energy into another is called transduction. For sensory transduction, a graded potential is produced, which can lead to an action potential if the stimulus is strong enough and the receptor is a part of a neuron. However, not all receptors are neurons (some are modified neurons or epithelial cells that can not produce an action potential). A graded potential in these receptor cells will stimulate a proportional release of neurotransmitter that will induce an action potential in a neighboring nerve cell.
Describe the synaptic junctions between the neurons of the autonomic and somatic nervous systems and their effector organs.
The neuroeffector junction describes the synapse between neurons of the autonomic nervous system and their effector organs. The anatomy of these structures is quite different from the typical neuron-neuron synapse. The postganglionic neuron does not have a discrete, well-defined axon terminal. Rather, those neurons contain numerous swellings along their length (varicosities). Within those varicosities, neurotransmitters (norepinephrine and acetylcholine) are synthesized and stored in vesicles, as occurs at axon terminals. However, while the swellings contain the voltage-gated calcium channels that are required for the release of neurotransmitter, they also contain the voltage-gated sodium and potassium channels that are required for the propagation of an action potential along the length of the axon. At the same time, the distance between a varicosity and the postsynaptic membrane is greater than what is observed in the synaptic cleft of other synapses. In the somatic nervous system, the synapse (neuromuscular junction) couples the motor neuron to skeletal muscle fibers. The terminal bouton of the motor neuron contains acetylcholine stored in vesicles. The motor end plate is a specialized region of the skeletal muscle that contains an invagination where nicotinic receptors are located. Surrounding this invagination are local regions of high acetylcholinesterase concentration.
When the doctor shines a penlight into the patient's eye, which of the following occurs?
The parasympathetic nervous system is activated, which causes contraction of the inner circular muscle of the iris and pupillary constriction.
Which of the following is an effect of parasympathetic activity to the heart? A) Postganglionic neurons release acetylcholine, which binds to nicotinic cholinergic receptors in the SA node. B) SA nodal cells are depolarized. C) Heart rate is increased. D) The rate of spontaneous depolarization in SA nodal cells decreases. E) cAMP is activated.
The rate of spontaneous depolarization in SA nodal cells decreases.
Taste involves a complex mixture of different receptors for particular classes of compounds that can be present in food. Describe how taste receptors are able to detect the four primary tastes.
The sensation of taste derives from chemoreceptors within the mouth. Those chemoreceptors are located within structures called taste buds on the tongue and roof of the mouth. Taste sensitive cells are modified epithelial cells with taste receptors that bind selectively to chemicals (tastants) in the food that we ingest. In order to bind, the chemical must be dissolved in saliva. There are four primary tastes: salt, sour, sweet, and bitter. Sour derives from the presence of hydrogen ions that block potassium channels, which causes the cells to depolarize. Salty foods are sensed by the increased electrochemical driving force for movement of sodium into the cell, which would cause the cell to depolarize. Sweet is mediated by the receptor linked to a G protein called gustducin, which binds to organic molecules such as sucrose to stimulate the production of cAMP. This activates a protein kinase that phosphorylates a potassium channel. This phosphorylation causes more potassium channels to remain in the closed state, thereby depolarizing the cell. Bitter is associated with detection of nitrogenous compounds. Bitter substances can be sensed by several different mechanisms: the direct binding to a receptor, which causes the closure of potassium channels, and the binding to a receptor that activates a G protein, called transducin. In that case, transducin activates the enzyme phospholipase C, which leads to the production of IP3. An increase in IP3 stimulates the release of calcium from the sarcoplasmic reticulum.
What are the three polys of diabetes mellitus and what is the cause of each?
The three polys are early symptoms of diabetes mellitus and include polyuria (excessive urination), polydipsia (excessive thirst), and polyphagia (excessive eating). Polyuria and polydipsia are ultimately caused by the same thing - a hyperglycemia induced osmotic gradient for more water to enter the renal tubules and be excreted. This directly causes polyuria, which decreases plasma volume and blood pressure. A drop in blood pressure will increase blood levels of angiotensin II, which acts on the anterior hypothalamus to trigger thirst causing polydipsia. Polyphagia is a direct result of decreased insulin activity as insulin as appetite suppressing effects in the hypothalamus. Hyperglycemia may also decrease release of cholecystokinin, a hormone released from the small intestine that acts in the hypothalamus to induce satiety.
List the three classes of receptors found in the skin (with an example of each with its function), and the pathways that those stimuli must follow to reach the somatosensory cortex.
The three types of skin receptors are mechanoreceptors, thermoreceptors, and nociceptors. Mechanoreceptors: Merkel's disks - pressure; Meissner s corpuscles - vibration; free nerve endings - light touch; Pacinian corpuscles - vibration; Ruffini's end organs - pressure. Thermoreceptors: cold and warm. Nociceptors: mechanical - intense mechanical; thermal - intense thermal; polymodal - intense mechanical or thermal stimuli; or specific chemicals. There are two main pathways by which sensory information will travel to the somatosensory cortex: the dorsal column-medial lemniscal pathway and the spinothalamic tract. The dorsal column-medial lemniscal pathway carries information from mechanoreceptors and proprioceptors. In this pathway, the first -order neurons enter the dorsal horn of the spinal cord where most of the collaterals from that neuron terminate. However, the main branch ascends the spinal cord within the dorsal column to the ipsilateral brainstem. That first-order neuron synapses in the dorsal column nuclei of the medulla with a second-order neuron. The second-order neurons cross over to the contralateral side of the medulla along the medial lemniscus and ascend to the thalamus. In the thalamus, the second-order neurons synapse with third-order neurons that transmit the information to the somatosensory cortex. The spinothalamic tract carries information from thermoreceptors and nociceptors. The first-order neurons enter the spinal cord at the dorsal horn and travel a short distance in either direction along the spinal cord within Lissauer s tract where they will synapse with second-order neurons. The second-order neurons cross over to the contralateral side and ascend to the anterolateral quadrant of the spinal cord and through the brainstem before they enter the thalamus. In the thalamus, the second-order neuron synapses with the third-order neuron, which ascends to the somatosensory cortex.
Describe the pathway whereby vibration, initiated by sound waves, reaches the cochlea.
The tympanic membrane is vibrated by sound waves that pass that vibration from the malleus to the incus and finally onto the stapes, which vibrates the round window of the cochlea.
Within the inner ear are several structures that are involved in equilibrium and balance. Describe these structures and how they are able to detect changes in velocity and direction.
The vestibular organs in the inner ear are composed of the semicircular canals (of which there are three) and two otolithic organs (utricle and saccule). They are able to detect a change in linear and rotational velocity (acceleration or deceleration). The vestibular apparatus is located within the temporal bone and consists of a membranous labyrinth that is filled with endolymph and is surrounded by perilymph. The three semicircular canals are located perpendicular to one another, allowing them to detect rotational movement of the head in three planes. The anterior canal detects rotation in the up and down direction, as when nodding yes. The posterior canal detects motion of the head from side to side, as when the ear moves toward the shoulder. The lateral canal detects rotation of the head from side to side, as when shaking the head to say no. These canals contain an enlarged region called the ampulla where the sensory cells are located. Within the ampulla is the cupula, a gelatinous mass in contact with the stereocilia that project from the hair cells. Bending of the stereocilia causes a change in membrane potential of the hair cell. The sterocilia are bent by endolymph pushing against the cupula. As the head is put into motion (accelerates), the endolymph lags behind, causing it to move within the canal, which pushes on the cupula. This movement of the cupula bends the stereocilia, thereby altering the membrane potential of the hair cell. If that acceleration of the head reaches a constant velocity (acceleration is an increase in velocity whereas deceleration is a decrease in velocity), the endolymph will stop moving within the canal as the head comes to a constant velocity and the stereocilia will no longer be stimulated. Any change in velocity (acceleration or deceleration) would cause the endolymph to move again within the canal and thereby stimulate the stereocilia. Otoliths are the small calcium carbonate crystals that are embedded within the gelatinous mass in contact with the stereocilia of the hair cells. The hair cells of the utricle are oriented horizontally with the stereocilia extending vertically, while the hair cells of the saccule are oriented vertically with the stereocilia extending horizontally. Thus, the utricle can detect forward and backward acceleration while the saccule detects upward and downward acceleration. Again, the otolith lags behind the movement of the body, causing the bending of the stereocilia of the hair cell that alters membrane potential of the hair cell.
Photoreceptive cells are located within the retina. Describe the general structure and the cells present within the retina, and how light is converted into electrical energy within rods and cones.
There are three distinct layers of cells within the retina: 1) an outer layer of rods and cones (the photoreceptive cells), 2) a middle layer of bipolar cells, and 3) an inner layer of neurons called ganglion cells. Light must pass through the second and third layers to reach photoreceptors. The bipolar cells, along with amacrine and horizontal cells, are involved in processing visual information, while the ganglion cells are the neural cells that transmit the visual information back to the visual center of the brain. The main difference between rods and cones lies in the photopigment that detects light and the sensitivity of that pigment to particular wavelengths of light. In rods, the photopigment is rhodopsin. The light-absorbing portion of the photopigment (rhodopsin) is retinal. The other portion of that protein (opsin) determines the sensitivity of rhodopsin to particular wavelengths of light. Rhodopsin is located within membranous disks that are associated with transducin and phosphodiesterase (which degrades cGMP). In the presence of cGMP, sodium channels on the cell membrane of the photoreceptor are more likely to be in the open state. In the dark, phosphodiesterase is relatively inactive, allowing cGMP to be elevated and sodium channels to be maintained in the open state, which depolarizes the photoreceptor. This depolarization stimulates voltage-sensitive calcium channels to remain open, which causes the release of neurotransmitter onto bipolar cells. When light impinges on rhodopsin, the opsin molecule bleaches, activating transducin, which activates phosphodiesterase. This will decrease the intracellular concentration of cGMP, causing sodium channels to close and the cell to hyperpolarize. This hyperpolarization closes the voltage-sensitive calcium channel, which decreases the release of neurotransmitter onto the bipolar cells. Rods are sensitive to low intensities of light, whereas cones require a greater intensity of light in order be activated. The same mechanisms that are active in the rods are active in the cones. The color sensitivity of cones derives from the three different forms of rhodopsin found in cones. These molecules are most sensitive to red, green, and blue wavelengths of light.
In human skeletal muscle, a number of different fiber types exist. Describe the properties of the fibers that make them unique and how that is linked to motor units.
There are three major types of muscle fiber in human skeletal muscle, which are characterized by their metabolic profile and speed of contraction. With respect to their metabolic profile, the enzymes expressed in these cells can favor either a glycolytic (substrate-level phosphorylation) or oxidative metabolism. Muscle fibers with a greater oxidative enzyme profile will contain a greater density of capillaries, increased mitochondrial density, higher myoglobin concentration, and will have a smaller diameter than glycolytic fibers. In contrast, glycolytic fibers are thicker (have a greater diameter) than oxidative fibers, contain fewer capillaries, and have a greater capacity to produce ATP under anaerobic conditions. Within a given motor unit, all of the muscle fibers are of the same fiber type, indicating that fiber type is determined by the motor neuron. The largest of the fibers are the fast glycolytic, while the smallest are the slow oxidative; the fast oxidative are intermediate. The same is true for the speed of contraction; the fast glycolytic are faster than fast oxidative, which are faster than slow oxidative. Motor units are also of different sizes; fast glycolytic are larger than fast oxidative or slow oxidative.
Describe the neural pathway of vision from the photoreceptor to the primary visual cortex. How are we able to perceive the three-dimensional character of the world around us?
Throughout the retina, varying numbers of photoreceptors converge onto a bipolar cell. These cells are capable of generating graded potentials, the nature of which is determined by the photoreceptor. Two types of photoreceptors are present within the retina: those that release excitatory neurotransmitters and those that release inhibitory neurotransmitters. As neurotransmitter release is reduced when the photoreceptor is activated by light, the bipolar cells are either depolarized or hyperpolarized. Thus, some bipolar cells are activated by light while others are inhibited by light. In addition, the synapse between the photoreceptor and bipolar cells can be modulated by horizontal cells. When depolarized, the bipolar cells release their neurotransmitter onto a ganglion cell. The direction of the response from the ganglion cell will depend upon whether the neurotransmitter from the bipolar cells is excitatory or inhibitory. Ganglion cells are the first-order neurons in the pathway of vision and are therefore the first cells capable of generating an action potential. The axons of the ganglion cells form the optic nerve and exit the eye at the optic disk. The two bundles of nerves combine at the base of the brain to form the optic chiasm. In the optic chiasm, half of the axons from each eye cross over. The cells from the nasal portion of the eye cross over to combine with the temporal portion of the eye from the other side. The ganglion cells terminate in the lateral geniculate body of the thalamus, where they synapse with the neurons that ascend to the primary visual cortex. Depth perception is dependent upon the brain receiving input from both eyes. The region of the visual field that is detected by both eyes is the binocular visual field. Within this area, we are able to perceive depth. The cortex uses the difference in angle between the visual field of both eyes to perceive a three-dimensional image.
Hypothalamic hormones
Thyrotropin-releasing hormone (TRH) Gonadotropin-releasing hormone (GnRH) Growth hormone-releasing hormone (GHRH) Corticotropin-releasing hormone (CRH) Somatostatin. Dopamine.
What type of junction would you expect to find most commonly in the intestinal tract, where exchange across epithelium is common?
Tight junctions
3-phosphoglycerate kinase
Transfers the high-energy phosphate from 1,3-bisphosphoglycerate to ADP, forming ATP and 3-phosphoglycerate
(T/F) In facilitated diffusion, the carrier protein has equal affinity for the molecule being transported on both sides of the membrane.
True
T/F A deficiency in the enzyme adenosine deaminase can lead to an immunodeficiency disease.
True
T/F Action potentials in cardiac muscle last longer than action potentials in skeletal muscle.
True
T/F Activation of Golgi tendon organs during overstretching of a muscle protects the muscle by inhibiting its contraction.
True
T/F All classes of antibodies are capable of neutralization of antigen
True
T/F Alpha adrenergic receptors have a greater affinity for norepinephrine than for epinephrine.
True
T/F Alpha motor neurons innervate extrafusal muscle fibers
True
T/F Auditory information is transmitted through the medial geniculate nucleus in the thalamus to the cortex.
True
T/F Capsaicin causes a burning sensation in the mouth because it binds to TRPV1 receptors.
True
T/F Cells expressing tumor antigens are attacked by cytotoxic T cells.
True
T/F Class II MHC molecules are found on macrophages.
True
T/F Clonal selection of B cells generally results in the production of two types of clones: plasma cells and memory cells.
True
T/F Contraction of smooth muscle cells is driven by binding of calcium to calmodulin
True
T/F Creatine phosphate provides an immediate source of high energy phosphate to donate to ADP at the onset of muscle activity.
True
T/F Cytokines released during illness can cause a person to be more sensitive to pain.
True
T/F Depth perception requires visual input from both eyes.
True
T/F Diabetic neuropathy can cause erectile dysfunction
True
T/F Extensive convergence of rods onto bipolar cells allows for greater sensitivity to light.
True
T/F Glycosylation decreases the ability of neutrophils and macrophages to phagocytose bacteria during inflammation.
True
T/F MHC molecules do not play a role in transfusion reactions because erythrocytes do not express the MHC molecule
True
T/F Macrophages are phagocytes that initiate inflammation.
True
T/F Modulation of sensory information as it is transmitted from receptors to the cerebral cortex can only occur at synapses.
True
T/F Oxidative phosphorylation is the primary energy source for cardiac muscle.
True
T/F Pacemaker activity occurs in certain smooth muscle cells and cardiac muscle cells.
True
T/F Ryanodine receptors are calcium channels in the sarcoplasmic reticulum.
True
T/F Sebaceous and sweat glands can act as a first line of defense because their secretions are acidic.
True
T/F Skeletal muscle fibers operate at near-optimal sarcomere length in situ.
True
T/F Smooth and cardiac muscle are innervated by the autonomic nervous system, whereas skeletal muscle is innervated by the somatic nervous system.
True
T/F Spontaneous depolarization of smooth muscle cells is mediated by pacemaker cells.
True
T/F The autonomic nervous system consists of efferent pathways with two peripheral neurons that travel in series from the central nervous system to the effector organ.
True
T/F The biceps cause flexion of the arm, whereas the triceps cause extension.
True
T/F The complement system can be activated by both specific and nonspecific defenses.
True
T/F The concentration of cGMP in a photoreceptor is relatively high in the dark, thereby maintaining rods and cones in the depolarized state.
True
T/F The proximity of the sarcoplasmic reticulum to each sarcomere permits the nearly simultaneous delivery of calcium to all sarcomeres of the muscle fiber.
True
Which of the following ion channels does NOT participate in the contractile cell action potential? A) type T calcium channels B) type L calcium channels C) delayed rectifying potassium channels D) inward rectifying potassium channels E) voltage-gated sodium channels
Type T calcium channels
Catecholamines are derived from what amino acid?
Tyrosine
Thyroid hormones are synthesized from what amino acid?
Tyrosine
Describe cell-mediated immunity, including the role of the MHC molecule.
Unlike humoral immunity, cell-mediated immunity does not rely on the indirect action of antibodies to kill cells. There are three major types of T cells involved in cell-mediated immunity: suppressor T cells, cytotoxic T cells, and helper T cells. Suppressor T cells are not well understood, and are thought to produce cytokines that suppress the activities of B cells, helper T cells, and cytotoxic T cells. Helper T cells are the primary regulators of immune function, because they use cytokines to activate B cells, cytotoxic T cells, suppressor T cells, and helper T cells. In addition, they secrete cytokines that enhance the activity of macrophages and natural killer cells. Cytotoxic T cells are directly responsible for cell-mediated immunity by killing cells infected with viruses, bacteria or other abnormal presentations. All three types have T cell receptors but they are only able to bind to cells when the antigen is presented with a major histocompatibility (MHC) molecule (known as human leukocyte antigen [HLA]). The MHC molecule that has bound to an antigen makes contact with a T cell receptor to activate the T cell. The coupling between the MHC molecule and antigen is referred to as antigen presentation. There are two general classes of MHC molecules: class I and class II. Class I MHC molecules are found on the surface of all nucleated cells, while class II are found on the surface of macrophages, activated B and T cells, and cells on the interior of the thymus. The MHC molecule is specific for an individual and allows the body to distinguish between self and nonself. The fidelity of the self signal is maintained within the thymus by the presence of class I and II MHC molecules. In order to continue to develop, a T cell must have an affinity for particular MHC molecules. T cells that bind to class I MHC molecules in the thymus develop into cytotoxic T cells, while those that bind to class II MHC molecules develop into helper T cells. As a newly synthesized MHC molecule makes its way to the membrane of an infected cell, it is able to capture antigen fragments from within the cell. Class I MHC molecules capture foreign or abnormal antigens within infected cells and tumor cells. Class II MHC molecules capture foreign antigens that have been internalized by phagocytosis or receptor-mediated endocytosis. Helper T cells express the CD4 protein on their surface that allows them to bind to class II MHC molecules, while cytotoxic T cells contain the CD8 protein, which binds to the class I MHC molecules. In cell-mediated responses, class II MHC molecule responses activate helper T cells by the release of interleukin-1, which causes the helper T cells to proliferate and differentiate into daughter cells, some of which become memory cells. Cytotoxic T cells are activated by two events occurring simultaneously: binding to class I MHC molecules and the release of interleukin-2 from the helper T cell. Once activated, the cytotoxic T cells release perforin, which creates pores in the membranes of pathogenic cells that cause them to lyse. The cytotoxic T cells can also release fragmentin that enters the cells and induces apoptosis. Cytotoxic T cells can also attack tumor cells expressing the class I MHC molecules.
Dihydroxyacetone phosphate (DHAP)
Used in hepatic and adipose tissue for triacylglycerol synthesis Formed from fructose 2,6-bisphosphate Can be isomerized to glycerol 3-phosphate, which can be converted to glycerol (the backbone of triacylglycerols)
Which of the following cranial nerves does NOT include parasympathetic nerves?
V - trigeminal nerve
Which cranial nerve transmits taste information to the central nervous system?
VII, IX, and X
Which of the following is TRUE of the ventricular filling phase of the cardiac cycle?
Ventricular pressure is less than aortic pressure.
Which of the following statements about lateral inhibition is FALSE?
Which of the following statements about lateral inhibition is FALSE?
Parasympathetic neurons from which cranial nerve innervate most of the viscera in the thoracic and abdominal cavities?
X
Anchors thin filaments together.
Z line
If damage to the AV node slowed down conduction through this tissue, what would be observed on an ECG?
a longer PR interval
What is a motor unit?
a motor neuron and all the muscle fibers it innervates
adenosine
a nucleoside; a combination of ribose and adenine; serves as a neuromodulator in the brain that promotes sleep, degraded by adenosine deaminase
Which of the following can NOT cause coma? A) a person with diabetes mellitus taking too much insulin causing hypoglycemia B) a person with diabetes mellitus type 1 taking too little insulin causing hyperglycemia C) a blood osmolarity greater than 350 mOsm D) a blood glucose concentration greater than 600 mg/dL E) a partial pressure of carbon dioxide of 40 mm Hg in arterial blood
a partial pressure of carbon dioxide of 40 mm Hg in arterial blood
What is an ectopic focus?
a site where an abnormal depolarization in cardiac muscle initiates an extrasystole
Binding of norepinephrine to what type of receptor will trigger the activation of phospholipase C?
a1
acromegaly
abnormal enlargement of the extremities caused by an increase in growth hormone in adults (usually due to anterior pituitary hormone)
What is parasthesia?
abnormal sensation of the skin such as tingling or numbness
Why do many diabetics have to have a foot amputated?
abnormal wound healing coupled to lack of sensation from the foot can lead to gangrene
What is the function of the retinal pigmented epithelium?
absorb light that enters the eye
In order to focus light coming from a near source onto the retina, the lens adjusts its refractive power through what process?
accommodation
19) What chemical group is transferred by Coenzyme A?
acetyl group
Released from motor neurons.
acetylcholine
Released from sympathetic preganglionics.
acetylcholine
Released from varicosities in the parasympathetic nervous system.
acetylcholine
Parasympathetic preganglionic neurons release the neurotransmitter ________; sympathetic preganglionic neurons release the neurotransmitter ________.
acetylcholine, acetylcholine
Parasympathetic postganglionic neurons release the neurotransmitter ________; sympathetic postganglionic neurons release the neurotransmitter ________.
acetylcholine, norepinephrine
What enzyme degrades the neurotransmitter released from varicosities of parasympathetic postganglionic neurons?
acetylcholinesterase
The contractile portion of the thin filament is composed of what protein?
actin
Describe the inflammatory response, including a discussion of the process of phagocytosis and the cytokines that mediate this response.
activated within the tissue by macrophages. These cells bind to bacteria and damaged cells, internalize them and degrade them with lysosomes (phagocytosis). The remains of this cellular degradation are released by exocytosis and stimulate cytokine secretion from macrophages, which contributes to the inflammatory response. This degradation product also stimulates mast cells to release histamine, which dilates arterioles (decreases resistance) and increases the permeability of capillary endothelial cells. The decreased resistance leads to increased blood flow and hydrostatic pressure, which causes the redness and elevated temperature that is characteristic of the inflammatory response. The elevated hydrostatic pressure and increased capillary permeability to proteins causes the tissue to swell (edema). That increased interstitial pressure can stimulate sensory nerve endings, causing the sensation of pain; sensory nerve endings are directly stimulated by the release of bradykinin as well. Heparin, released from basophils and mast cells, inhibits the activity of clotting factors. In time, the clotting factors become active, thereby isolating the damaged region of tissue. The cytokines released by the initial phagocytosis affect endothelial cells, causing them to increase their production of selectins. These selectin proteins are involved in margination, the slowing of leukocytes as they move through the vasculature of the injured tissue. Once leukocytes are slowed, the increased expression of integrins on those leukocytes will bind them tightly to endothelial cells. Expression of integrins is stimulated by interleukin-1, interleukin-6, and tumor necrosis factor- . This attachment allows leukocytes to move across the endothelial cell wall and to the site of infection by the process of diapedesis. Leukocytes are drawn to the site of infection by cytokines through the process of chemotaxis. The bacteria and debris are destroyed through phagocytes by leukocytes (neutrophils and macrophages) that have entered. They are stimulated to bind to damaged cells by their appearance and their adhesion is enhanced by opsonization, which involves proteins (antibodies and others proteins) binding to the cell and enhancing leukocyte binding.
The increased influx of calcium at a postsynaptic terminal with glutamate receptors ________.
activates a protein kinase that phosphorylates the AMPA receptor, making it more sensitive to glutamate
Interferon- is secreted by ________ and enhances ________.
active T cells and natural killer cells; macrophage phagocytosis
In response to certain cytokines, the liver secretes ________, which help combat bacterial infections and induce inflammation.
acute phase proteins
In the presence of a stimulus of constant intensity, a decrease in the magnitude of a graded potential within a sensory receptor over time is called ________.
adaptation
Includes the steps of margination, attachment, diapedesis, and chemotaxis
additional leukocytes are recruited to the region
What neurotransmitter appears to be involved in initiating slow-wave sleep?
adenosine
Which of the following proteins is directly activated by a G protein? A) phospholipase A2 B) adenylate cyclase C) tyrosine kinase D) calmodulin E) protein kinase G
adenylate cyclase
Which of the following would NOT be found within the gray matter of the spinal cord? A) interneurons B) afferent neuron cell bodies C) efferent neuron cell bodies D) efferent neuron dendrites E) axon terminals from afferent neurons
afferent neuron cell bodies
What is the function of the ear ossicles?
amplify sound waves as they are transmitted from the middle to the inner ear
Enlarged area at the base of the semicircular canals; contains hair cells.
ampulla
Located within the ________ of the semicircular canal, a gelatinous structure called the ________ surrounds the stereocilia and kinocilium.
ampulla : cupula
Which of the following is NOT an adaptation of skeletal muscle that would be observed in response to aerobic training?
an increase in the diameter of the skeletal muscle fibers
The lateral displacement of bipolar and ganglion cells within the macula lutea allow for ________.
an unhindered pathway for light to reach the cones of the fovea
What is the only mechanism of ATP production in erythrocytes?
anaerobic glycolysis (b/c RBCs dont have mitochondria)
The absence of pain, but not other somatosensations, is called (anesthesia/analgesia)
analgesia
In diabetes mellitus, polydipsia is triggered by what hormone?
angiotensin 2
________ is an amino acid neurotransmitter at excitatory synapses whereas ________ is an amino acid neurotransmitter at inhibitory synapses.
aspartate, glycine
Which of the conditions below describes irregularities in the structure of the cornea or lens? A) cataracts B) presbyopia C) glaucoma D) astigmatism E) hyperopia
astigmatism
Which of the following defects in vision is incorrectly matched with its cause?
astigmatism : hardening of the lens
What type of glial cell is necessary for normal development of the blood-brain barrier?
astrocytes
What type of glial cell contributes to neurodegenerative diseases, such as Alzheimerʹs disease?
astrocytes and microglia
Contraction of motor units in a(n) ________ manner allows a muscle to maintain a level of force for a duration of time without fatiguing.
asynchronous
50) The small increase in ventricular pressure observed late in diastole is caused by ________.
atrial contraction
Compared to norepinephrine, epinephrine has a greater affinity for what type of receptor?
beta2
Epinephrine binds best to which of the following receptor types?
beta2 adrenergic receptors
Name the antagonistic muscle to the triceps.
biceps
Reducing glucose production in the liver and increasing the sensitivity of receptors to insulin.
biguanides
What causes DNA to uncoil during transcription?
binding of RNA polymerase to the promoter sequence (PRECEDES helicase)
Photoreceptors transmit information directly to ________ cells via the release of a neurotransmitter, causing those cells to develop a(n) ________ potential proportional to the intensity of the stimulus.
bipolar, graded
Red blood cells have _____________, which produces 2,3 bisphosphoglycerate from 1,3 bisphosphoglycerate in glycolysis
bisphosphoglycerate mutase
Cones that respond to the shortest wavelengths of light (S cones) respond best to what color spectrum?
blue
Name the two central lymphoid tissues.
bone marrow and thymus
B cells are tested for their ability to bind to self in the ________ and are removed by ________ if they do bind to self.
bone marrow, apoptosis
(sympathetic/parasympathetic/both/neither) releases acetylcholine from its preganglionic fibers.
both
(taste/olfaction/both) Molecules must be dissolved in fluid to interact with receptor.
both
Active at rest (sympathetic/parasympathetic/both/neither)
both
decreased heart and respiration rate occurs in REM sleep, slow wave sleep, or both?
both
Opening of which of the following channels contributes to the spontaneous depolarization of pacemaker cells?
both calcium channels and funny channels
Which of the following ion channels must open for a cardiac pacemaker cell to depolarize to threshold for an action potential?
both funny channels and T-type calcium channels
Fast EPSPs are produced at which of the following types of receptor?
both nicotinic cholinergic and AMPA receptors
Which of the following classes of chemical messengers moves to the target cell by diffusion?
both paracrine and neurotransmitter
Contains retinal.
both rods and cones
Where are gap junctions commonly found?
both single-unit smooth muscle and cardiac muscle
Dual innervation of organs by the autonomic nervous system refers to the observation that ________.
both sympathetic and parasympathetic neurons innervate most organs
What layer of the adrenal cortex secretes androgens?
both zonae reticularis and fasciculata
Lipophilic hormones are transported in blood ________ and bind to receptors located ________.
bound to carrier proteins, inside the cell
Location of gustatory nucleus
brainstem
Location of vestibular nuclei
brainstem
Most pyramidal tract neurons cross to the opposite side of the body in what region?
brainstem
Where are most of the autonomic nervous system control centers located?
brainstem
Where the dorsal column pathway crosses over to the opposite side.
brainstem
Where in the central nervous system do the preganglionic neurons of the parasympathetic nervous system originate?
brainstem and sacral region of the spinal cord
Which area of the brain is involved in control of posture?
brainstem nuclei
In the process of agglutination, IgD antibodies ________. A) remove the antigen from the pathogen B) block access to the antigenic site C) bind to antigens on two different cells D) stimulate the release of histamine from mast cells E) activate the complement system
c) bind to antigens on two different cells.
The closure of sodium channels is mediated by a decrease in the cytosolic concentration of ________, which is degraded by ________.
cGMP : phosphodiesterase
What hormone released from the thyroid gland regulates blood calcium?
calcitonin
The mass of the gelatinous material within the saccule and utricle is enhanced by the presence of what type of crystals?
calcium carbonate
In order to allow discrete contractile events to occur, calcium is rapidly removed from the cytoplasm via ________.
calcium pumps (active transport of calcium)
Binds calcium in smooth muscle cells.
calmodulin
In smooth muscle, calcium triggers contraction by binding to what protein?
calmodulin
In smooth muscle, calcium binds to ________, and then activates the enzyme ________.
calmodulin : myosin light-chain kinase
Dietary control of diabetes mellitus type 1 includes limiting the intake of ________.
carbohydrates
Cardiomyopathy is a disease caused by decreasing
cardiac muscle contractility
Name the sympathetic collateral ganglia
celiac, superior mesenteric, and inferior mesenteric
Which of the regions of the brain listed below is NOT involved in the control of the autonomic nervous system?
cerebellum
Recruited leukocytes that have invaded the vessel wall are directed to the pathogen by the process of
chemotaxis
Cerebrospinal fluid is produced within the ________ and is reabsorbed into the venous circulation by special structures called the ________.
choroid plexus, arachnoid villi
Muscle under parasympathetic control to regulate the refractive power of the lens.
ciliary muscles
The process of antigen-induced lymphocyte proliferation is called ________.
clonal selection
In comparison to low pitch sound, high pitch sound will cause vibrations of the basilar membrane ________.
closer to the oval window
The transduction of sound waves into neural impulses occurs in the ________.
cochlea
This structure includes the scala media, scala tympani, and scala vestibuli.
cochlea
During T cell development in the thymus, those cells with receptors for class I major histocompatibility molecules develop into ________ T cells, whereas those with receptors for class II major histocompatibility molecules develop into ________ T cells.
cytotoxic, helper
Which of the following is NOT a symptom of ketoacidosis? A) dehydration B) fruity odor to breath C) decreased ventilation D) polyuria E) electrolyte imbalance
decreased ventilation
What effect does diabetes have on wound healing?
delays it by slowing the rate of all phases
Somatostatin is made in the
delta cells of the pancreas (inhibits the secretion of other pancreatic hormones such as insulin and glucagon) AND hypothalamus (inhibits the pituitary gland's secretion of growth hormone and thyroid stimulating hormone).
In smooth muscle, the structures analogous to Z lines in skeletal muscle are called ________.
dense bodies
The opening of a cation channel that allows both Na+ and K+ to move through will cause the membrane to ________ because of the ________.
depolarize : greater Na+ electrochemical gradient as compared with K+
In the absence of light, the membrane potential of a photoreceptor is relatively ________ by the presence of open ________ channels.
depolarized : sodium
The body surface is mapped into ________, which are regions that receive sensory information from particular spinal nerves.
dermatomes
What is angiogenesis?
development of new blood vessels
What is the leading cause of adult-onset blindness in the United States?
diabetic retinopathy
Which of the following second messengers, when released by phospholipase C, will directly activate the enzyme protein kinase C?
diacylglycerol
________ is the process whereby leukocytes move across the endothelial layer and through the blood vessel wall.
diapedesis
What structure separates the thoracic cavity from the abdominal cavity?
diaphragm
The opening and closure of the atrioventricular and semilunar valves is driven by ________.
differences in pressure across the valve
Increases in the amount of cytoplasmic calcium required to initiate a muscle contraction are mediated by the coupling between a ________ on the T tubule and a ________ on the membrane of the sarcoplasmic reticulum.
dihydropyridine receptor : ryanodine receptor
Bending of the stereocilia on the hair cell can induce either a closure or an opening of a potassium channel based upon the ________.
direction that the stereocilia move
Whether the hair cell in the semicircular canal is depolarized or hyperpolarized is dependent upon which of the following?
direction toward which the stereocilia are bent relative to the kinocilium
Cells that secrete epinephrine must contain which enzymes?
dopamine β-hydroxylase, tyrosine β-hydroxylase, phenylethanolamine N-methyl transferase, and dopa decarboxylase
When the alpha subunit of the G protein is activated, it can stimulate ion channels to do what?
either open or close
The change in membrane potential that occurs in skeletal muscle cells in response to acetylcholine binding to its receptors is called a(n) ________.
end plate potential
The β1 adrenergic receptor has the greatest affinity for what messenger?
epinephrine and norepinephrine equally
The sequence of events that links the action potential to changes in skeletal muscle force development is called what?
excitation-contraction coupling
What neural pathway provides for the control of large muscle groups that function in posture and balance?
extrapyramidal tract
What cell type secretes collagen as a wound heals?
fibroblasts
The sympathetic nervous system mediates the ________ response as a consequence of its ability to prepare the body to cope with threatening situations.
fight-or-flight
Another name for an afferent neuron is ________.
first order neuron
What is the principle region of the brain involved in the induction of slow-wave sleep?
forebrain
___________ is delayed by heparin released from mast cells and basophils.
foreign matter being contained
This process involves activation of clotting factors.
foreign matter is contained
Microtubules
form the spindle fibers that are involved in the distribution of chromosomes during cell division. Microtubules are also the primary component of cilia and flagellahair-like protrusions involved in motility.
Site of highest visual acuity.
fovea
Cytotoxic T cells release (perforins / fragmentins), which enters bacterial cells and induces (lysis / apoptosis).
fragmentins, apoptosis
Somatosensory receptors that lack identifiable specialized structures are called ________.
free nerve endings
Slow gated channels are identified as such because, once the receptor is bound by the ligand, the receptor must first activate a(n) ________ prior to the channel opening or closing.
g protein
Lactulose
galactose and fructose
lactose is composed of
galactose and glucose
What type of motor neuron innervates intrafusal muscle fibers?
gamma
The synthesis of glucose from non-carbohydrate precursors is called ________ and it occurs in the ________.
gluconeogenesis, liver
Chitobiose
glucosamine + glucosamine
Trehalose
glucose + glucose
In order to convert the amino acid glutamate to gamma-amino butyric acid, cells must produce the enzyme ________ that catalyzes this reaction.
glutamic acid decarboxylase
Adrenergic neurotransmitters bind to both (1 & 2) and (1, 2 & 3) receptors with different affinities. Outline the affinities of these receptors for adrenergic neurotransmitters and characterize their activity as excitatory or inhibitory.
greater affinity for norepinephrine - 1 & 2 (excitatory) greater affinity for epinephrine - 2 (inhibitory) equal affinity for norepinephrine and epinephrine - 1 & 3 (excitatory)
orexin
hypothalamic neuropeptide that triggers hunger and alertness
What ensure(s) that blood levels of a specific releasing hormone are locally high in order to stimulate the pituitary?
hypothalamic pituitary portal system
The secretion of hormones from the anterior pituitary is controlled by
hypothalamic tropic hormones
Hunger and satiety centers located here.
hypothalamus
In which region of the brain does histamine function as a neurotransmitter?
hypothalamus
What area of the brain initiates the fight-or-flight response by producing widespread activation of the sympathetic nervous system?
hypothalamus
Which of these brain structures, outside of the cortex, is NOT involved in assisting with motor programming and providing feedback on the execution of a motor program? A) cerebellum B) thalamus C) basal nuclei D) hypothalamus E) brainstem nuclei
hypothalamus
the emotions of anger and aggression appear to originate primarily from within what area of the brain?
hypothalamus
Neuropeptides are synthesized in what region of a neuron?
in the rough endoplasmic reticulum
Since the creatine phosphorylation reaction is substrate driven, an increase in the concentration of creatine within a skeletal muscle fiber will directly have what effect?
increase creatine phosphate concentration
During rapid eye movement sleep, there is a(n) ________ in frequency of the electroencephalogram and a(n) ________ in arousal threshold.
increase, increase
A person has a tumor in the anterior pituitary causing a decrease in ACTH secretion. Which of the following correctly describes changes in plasma levels of hormones?
increased CRH, decreased ACTH, and decreased cortisol
A person has a tumor in the hypothalamus causing an excess in TRH secretion. Which of the following correctly describes changes in plasma levels of hormones?
increased TRH, increased TSH, and increased thyroid hormones
Which of the following physiological responses are associated with elevated sympathetic nervous system activity?
increased contractile force of the heart
Which of the following would NOT result from an increase in ventricular contractility?
increased end-diastolic volume
Which of the following contribute to diabetes enhanced atherosclerosis?
increased lipid transport in LDLs increased production of reactive oxygen species increased glycosylation microvascular disease
The increased aortic pressure that occurs during systole reflects a(n) ________.
increased volume of blood in the aorta
During slow-wave sleep, there is a progressive ________ in the strength of stimulus required to awaken a person and a(n) ________ frequency of electroencephalogram (EEG) activity, indicative of a synchronization of EEG activity.
increased, reduced
What is the correct order of the three steps of wound healing?
inflammation - proliferation - remodeling
What phases of wound healing is/are delayed in diabetes mellitus?
inflammatory and proliferative
What is the hormone whose release is stimulated by follicle stimulating hormone (FSH) in men?
inhibin (One of two hormones (designated inhibin-A and inhibin-B) secreted by the gonads (by Sertoli cells in the male and the granulosa cells in the female) and that inhibit the production of follicle-stimulating hormone (FSH) by the pituitary gland.)
What molecule, whose synthesis is catalyzed by phospholipase C, triggers the release of calcium from the endoplasmic reticulum?
inositol triphosphate
What is the primary medicine for regulating diabetes mellitus type 1?
insulin
Which of the following chemical messengers induces the sensation of feeling full (satiety effect)? A) insulin B) glucagon C) epinephrine D) acetylcholine E) somatostatin
insulin
_______________ are secreted by the liver and function to promote tissue growth.
insulin-like growth factors
At the site of infection, leukocytes are stimulated to express ________, which causes them to attach to the endothelial cells before moving into the vessel wall.
integrins
One of the characteristic signs of cerebellar damage is ________, a sometimes violent shaking that occurs when a person makes a voluntary movement.
intention tremor
Secreted by virally infected cells to induce a virus-resistant state in nearby cells.
interferon alpha
Secreted by active T cells and natural killer cells, this cytokine inhibits viral replication, enhances phagocytosis in macrophages, boosts production of antibodies by B cells, and activates both natural killer cells and cytotoxic T cells.
interferon-gamma
Helps induce proliferation and differentiation of B cells and T cells, stimulates release of acute phase proteins, and acts on the hypothalamus to induce fever.
interleukin-1
This cytokine stimulates plasma cell secretion of IgE and IgG, and increases the number of class II MHC molecules on B cells and macrophages.
interleukin-4
This cytokine stimulates plasma cells to secrete IgA
interleukin-5
Myosin is a type of (microfilament / intermediate filament / microtubule).
intermediate filament
the gray matter contains
interneurons, efferent neurons (dendrites and cell bodies), and axon terminals of afferent neurons. The gray matter is organized into the dorsal and ventral horn, with the dorsal horn containing the terminal axon of afferent neurons (the cell bodies of those neurons are located within the dorsal root ganglia). The ventral horn contains the cell bodies of the efferent neurons that travel to the periphery and synapse with skeletal muscle. In the thoracic and upper lumbar regions of the spinal cord, there is also a lateral horn (intermediolateral cell column) from which the efferent neurons of the autonomic nervous system originate.
Within the autonomic ganglia, what are the cells that modulate the flow of information to the target organ called?
intrinsic neurons
The velocity at which a skeletal muscle contracts is (directly / inversely) related to load.
inversely
Is the AMPA receptor ionotropic or metabotropic
ionotropic
Is the alpha adrenergic receptor ionotropic or metabotropic
ionotropic
Is the beta 1 adrenergic receptor ionotropic or metabotropic
ionotropic
The amount of light that impinges on the retina is primarily regulated by what structure?
iris
The ganglion cells of the retina synapse with neurons in the ________ that ascend to the ________. A) hypothalamus : primary visual cortex B) thalamus : primary motor cortex C) lateral geniculate body : cerebellum D) thalamus : primary somatosensory cortex E) lateral geniculate body : primary visual cortex
lateral geniculate body : primary visual cortex
Which of the following cortical regions is NOT involved in the development of a motor program? A) limbic system B) premotor area C) supplementary motor area D) primary motor cortex E) somatosensory area
limbic system
Are thyroid hormones lipophilic or lipophobic
lipophilic
Of the following areas of the body, which has the greatest tactile acuity?
lips
GLUT 2
low affinity glucose transporter found on *hepatocytes and pancreatic cells* -liver cells and in the Betal Islet Cells captures the excess glucose primarily for storage when glucose concentration drops below the Km for this transporter (has a high KM - low affinity for glucose - takes a lot of glucose to bind to this transporter) - it will go past the liver and straight into the periphery the liver will only pick up EXCESS glucose and store it - preferably right after a meal when glucose concentration exceeds the KM this transporter and glucokinase serves as the glucose sensor for insulin RELEASE in the Beta Islet cells of the pancreas
Phagocyte that initiates inflammation
macrophages
These are the first cells in the wound area and they contribute to inflammation while fighting the infection through phagocytosis and secreting cytokines.
macrophages
What cell type initiates inflammation?
macrophages
Phagocytosis of debris in the area of wound is carried out by what cell types?
macrophages and neutrophils
During this process, cytokines are released to initiate inflammation.
macrophages engulf debris and foreign matter
The ________ is an indentation in the retina that contains the fovea.
macula lutea
Which of the following is NOT a cell type found in the retina?
macular cells
48) Angiogenesis contributes to the cause of what visual defect in diabetes? A) macular degeneration B) glaucoma C) myopia D) hyperopia E) cataracts
macular degeneration
What type of cell found in the skin and mucosal linings secretes histamine?
mast cell
What region of the adrenal gland secretes epinephrine?
medulla
Cells of the adrenal (medulla / cortex) that release epinephrine are called ________.
medulla : chromaffin cells
The primary afferent neurons from taste receptor cells terminate within what structure of the central nervous system?
medulla oblongata
The complement system consists of several proteins that form a (n) ________ that forms a pore in the membrane of bacteria during the nonspecific immune response.
membrane attack complex
Where does beta oxidation occur?
mitochondrial matrix
Where does pyruvate get converted to lactatte
mitochondrial matrix
The form of energy associated with a particular stimulus type.
modality
What two enzymes catalyze the breakdown of catecholamines?
monoamine oxidase and catechol-O-methyltransferase
What type of cell, once it enters the tissues, is converted into a macrophage that attacks invaders by phagocytosis?
monocyte
Mismatches between vestibular, visual, and proprioceptive sensory inputs activate the autonomic nervous system, leading to symptoms that are characteristic of ________.
motion sickness
Contains nicotinic cholinergic receptors.
motor end plate
The region of skeletal muscle underlying the terminal bouton of a motor neuron is called the
motor end plate
Where on skeletal muscle is the highest density of nicotinic receptors?
motor end plate
Binding of acetylcholine to ________ receptors will activate a G protein.
muscarinic
What cholinergic receptors are coupled to G proteins?
muscarinic
Another name for a muscle cell is (myofibril / muscle fiber).
muscle fiber
A stroke occurring in the basal nuclei could produce which symptoms?
muscle rigidity
What type of receptor detects muscle length?
muscle spindle
What molecule present primarily within oxidative skeletal muscle cells acts as an oxygen buffer due to its ability to bind oxygen?
myoglobin
What is a condition where light, originating from a distance, is focused in front of the retina?
myopia
Calcium binding to calmodulin causes phosphorylation of what protein in what type of muscle?
myosin in smooth muscle only
In the optic chiasm, ganglion cells from the ________ portion of the retina cross over, whereas the ganglion cells from the ________ portion of the retina remain on the same side.
nasal, temporal
__________________ secrete perforins as part of the nonspecific defense mechanism.
natural killer cells
In the body, the sarcomere length of skeletal muscle cells is usually ________.
near optimal
Caused by damage to alpha cells of the pancreas
neither
Whereas the contractile activity of skeletal muscle is called ________, that of cardiac muscle is ________ because the contraction originates within the musculature itself.
neurogenic : myogenic
These cells arrive at the wound area by chemotaxis and assist in fighting the infection through phagocytosis and secreting cytokines.
neutrophils
What type of leukocytes are phagocytes?
neutrophils, eosinophils, and monocytes
Receptor types at the motor end plate are (muscarinic / nicotinic) cholinergic receptors.
nicotinic
Which class of autonomic nervous system receptors is ionotropic?
nicotinic cholinergic
Binding of acetylcholine to ________ receptors causes a ________ by opening channels that permit both sodium and potassium to permeate the membrane.
nicotinic, depolarization
(Nociceptors / warm receptors) respond best to temperatures greater than 44 °C.
nociceptors
What are sensory receptors that respond to tissue-damaging stimuli or stimuli that have the potential to damage tissue called?
nociceptors
during 3rd degree heart block
none of the electrical signals reach the ventricles. This type also is called complete heart block or complete AV block. When complete heart block occurs, special areas in the ventricles may create electrical signals to cause the ventricles to contract. This natural backup system is slower than the normal heart rate and isn't coordinated with the contraction of the atria. On an EKG, the normal pattern is disrupted. The P waves occur at a faster rate, and it isn't coordinated with the QRS waves. Complete heart block can result in sudden cardiac arrest and death. This type of heart block often requires emergency treatment. A temporary pacemaker might be used to keep the heart beating until you get a long-term pacemaker.
________ are proteins that fuse adjacent cells together to form a nearly impermeable barrier.
occludins
(taste/olfaction/both) Synapses with second-order neurons in glomeruli.
olfaction
Which sensory system does not need to transmit information through the thalamus to get to the cortex?
olfaction
What molecules within the mucus of the olfactory epithelium carry odorants to the receptor on the cilia?
olfactory binding proteins
Which of the following contributes to the ability of the sympathetic nervous system to produce widespread responses within the body?
one preganglionic neuron sends collaterals to multiple ganglia, affecting multiple postganglionic neurons
The transition from slow depolarization to an action potential in pacemaker cells is driven by the ________ of the ________ channel.
opening : L-type calcium
The presence of cGMP in the cytosol of a photoreceptor will directly stimulate the ________
opening of sodium channels
crossed extensor reflex
opposite limb supports body during withdrawal of injured limb
Proteins that bind to foreign matter making it easier for phagocytosis are called ________.
opsonins
The attachment of phagocytic cells to damaged/infected cells is facilitated by the presence of ________ on the damaged cell.
opsonins
Light striking this region of the retina is not detected by photoreceptors.
optic disk
The neural pathway from the lateral geniculate body to the visual cortex is called the ________.
optic radiations
This structure sits on the basilar membrane and contains the hair cells for sound.
organ of Corti
Disks of a photoreceptor are located in the ________ and contain ________.
outer segment, photopigment
hormones released from the posterior pituitary
oxytocin, vasopressin
What is the adequate stimulus for nociceptors?
pain
What vitamin is coenzyme A derived from
pantothenic acid
Histamine is an example of a (paracrine / hormone)
paracrine
What is a tingling sensation of the skin called?
parasthesia
(sympathetic/parasympathetic/both/neither) Ganglia are located in or near the effector organ.
parasympathetic
(sympathetic/parasympathetic/both/neither) Preganglionic fibers originate in the brainstem
parasympathetic
Rapid eye movement (REM) is called paradoxical sleep because ________.
people are more likely to awaken spontaneously during REM sleep when arousal threshold is highest
Natural killer cells secrete ________, which forms pores in the membrane of infected or abnormal cells.
perforins
Diabetic neuropathies generally affect what area of the nervous system?
peripheral nervous system
Does diabetic neuropathy affect the central nervous system, peripheral nervous system, or both?
peripheral nervous system
A hormone is ________ when a second hormone is required for the first hormone to have any activity.
permissive
At the site of a wound, neutrophils remove debris by what process?
phagocytosis
________ receptors are better able to provide information on whether a stimulus has changed, whereas ________ receptors are better adapted to provide information on the extent of that change.
phasic, tonic
pyruvate kinase
phosphoenolpyruvate to pyruvate, activated by fructose 1,6-BP from the PFK-1 reaction.
PFK2
phosphofrunctokinase 2 activated by *insulin* inhibited by *glucagon* fructose 6 phosphate --> fructose 2,6 phosphate fructose 2,6 phosphate activates PFK1 found mostly in the liver by activating this (due to insulin) it allows PFK1 to be activated and continued even though there is enough ATP - allows the production of glycogen, fatty acids and storage molecules to be made - allows storage, and not just ATP to be burned
__________ catalyzes synthesis of diacylglycerol and inositol triphosphate.
phospholipase C
What type of receptor responds to chemicals like histamine and bradykinin that are released from damaged tissue?
polymodal nociceptors
Which type of nociceptor is associated with C fibers?
polymodal nociceptors
What is the principle region of the brain involved in the initiation of rapid eye movement (REM) sleep?
pons
Which of the following is NOT a property of glycolytic fibers as compared to oxidative fibers?
poor ability to produce ATP in the absence of oxygen
The release of an inorganic phosphate from the myosin molecule directly results in which of the following?
power stroke
What causes some muscle fibers to appear red?
presence of myoglobin
Ejection of blood from the right ventricle will continue until ________.
pressure in the pulmonary artery is greater than pressure in the right ventricle
Active immunity through a natural pathway involves
previous exposure to the antigen
What anterior pituitary hormone is NOT a tropic hormone?
prolactin
Which of the following tropic hormones is a catecholamine? A) prolactin-releasing hormone B) prolactin-inhibiting hormone C) growth hormone-inhibiting hormone D) growth hormone E) luteinizing hormone
prolactin inhibiting hormone
Which of the following is an early sign of diabetic nephropathy?
proteinuria
What blood vessel carries deoxygenated blood to the lungs?
pulmonary artery
In response to light, activation of the pupillary light reflex causes
pupil constriction
In the visual system, activation of the parasympathetic nervous system causes which of the following?
pupillary constriction and an increase in the refractive power of the lens
What neural pathway provides for the control of fine, discrete movements of the extremities?
pyramidal tract
hat is an increase in the number of active motor units that would increase the force developed by a skeletal muscle called? A) Recruitment B) Summation C) Treppe D) Tetanus E) Length-tension relationship
recruitment
Secretion of hormones from the anterior pituitary is stimulated by ________ released from the ________.
releasing hormones, hypothalamus
Collagen becomes organized and cross-linked during what phase of wound healing?
remodeling
What is the function of the sodium-calcium exchanger in cardiac muscle?
remove calcium from the cytosol by transporting it to the extracellular fluid
Which of the following is NOT a function of TRP channels? A) warm transduction B) cold transduction C) respond to painfully hot stimuli D) respond to painfully hot chemicals E) respond to painful mechanical stimulation
respond to painful mechanical stimulation
Name the three nuclei located within the brainstem that are involved in the control of involuntary posture.
reticular formation, vestibular nuclei, red nuclei
The light-absorbing portion of the photopigment is ________; its sensitivity to a particular wavelength of light is altered by ________.
retinal : opsin
Pigmented structure that absorbs light waves.
retinal pigmented epithelium
Damage to the microvasculature that occurs with diabetes contributes to which of the following conditions?
retinopathy, nephropathy, neuropathy, delayed wound healing
(Rods/cones) have a greater degree of convergence with bipolar cells.
rods
(rods/cones) Is more sensitive to light.
rods
Contains rhodopsin (gpcr that is extremely light sensitive; enables vision in low-light conditions)
rods
_______ is the most abundant in the retina
rods
When we enter a dark room, the retinal and opsin molecules within the ________ must first ________ before low light levels can be detected.
rods : associate
The fundamental repeating unit of the myofibril called a ________ gives skeletal muscle its striated appearance, and is bordered by ________.
sarcomere : Z lines
Contains ryanodine receptors
sarcoplasmic reticulum
What is the saclike membranous network that surrounds each myofibril called?
sarcoplasmic reticulum
What chamber(s) of the cochlea contains endolymph?
scala media
Abnormal hormone secretions from an endocrine gland due to altered tropic hormone release are called ________.
secondary secretion disorders
For leukocytes to battle an infection, adhesion molecules are necessary including ________, which loosely bind leukocytes to the blood vessel wall slowing down their movement, and ________, which tightly attaches leukocytes to the blood vessel wall in preparation for diapedesis.
selectin, integrin
Detects rotational acceleration of the head.
semicircular canals
The increase in interstitial hydrostatic pressure associated with an edema will lead to a(n)
sensation of pain
What is an annulospiral ending?
sensory endings in the muscle spindle that detect muscle length
List the five components of a reflex arc.
sensory receptor, afferent neuron, integration center, efferent neuron, effector organ
A ________ refers to a single afferent neuron and all of the sensory receptors associated with that neuron.
sensory unit
In a _______________, a tropic hormone from the anterior pituitary inhibits the release of its own releasing hormone from the hypothalamus.
short negative feedback loop
Contracts by the sliding-filament mechanism
skeletal, smooth, and cardiac muscle
During skeletal muscle contraction, as the muscle shortens, the thick and thin filaments ________.
slide past one another
Postural muscles of the legs and back tend to have a high proportion of this fiber type.
slow oxidative
Which of the following is the correct order of muscle fiber recruitment from first to last?
slow oxidative : fast oxidative : fast glycolytic
Identify the three types of muscle fibers that are found in all skeletal muscles.
slow oxidative, fast oxidative, and fast glycolytic
Catalyze hydrolysis of ATP slowly.
slow twitch muscle
Some cells have pacemaker activity.
smooth and cardiac muscle only
Which of the following muscle types has the slowest contraction time?
smooth muscle
The chemical force for which ions is directed into the cell?
sodium and calcium
Which of the following is a neurotransmitter responsible for the transmission of a painful stimulus between first- and second-order neurons?
substance P
Close potassium channels on pancreatic beta cells causing a depolarization that triggers insulin release by exocytosis.
sulfonylureas
What type of cells in the olfactory mucosa maintain the extracellular environment surrounding the receptor cells?
sustentacular cells
(sympathetic/parasympathetic/both/neither) Preganglionic axons are short, traveling from central nervous system to a chain of ganglia.
sympathetic
Releases norepinephrine (sympathetic/parasympathetic/both/neither)
sympathetic
Which of the following neurons of the efferent branch of the peripheral nervous system does NOT release acetylcholine?
sympathetic postganglionic neuron
Transmits action potentials to the interior of the muscle cell to trigger calcium release.
t tubules
(taste/olfaction/both) Receptor cells are modified epithelial cells.
taste
Tips of stereocila for sound are embedded in this structure.
tectorial membrane
During what phase of cell division do two new nuclear envelopes begin to redevelop?
telophase
Intermediate filaments
tend to be stronger and more stable than microfilaments, and include proteins like keratin (located in the skin) and myosin. The largest of the cytoskeletal proteins are microtubules, which are composed of proteins called tubulin.
What structure composed of connective tissue transmits force from contracting skeletal muscle to bone?
tendon
What connects muscles to bone?
tendons
What chemical targets CB1 receptors?
tetrahydrocannabinol (primary endogenous agonist is anandamide)
Location of medial geniculate body
thalamus
Termination of second-order neurons.
thalamus
What region of the diencephalon filters and refines sensory information, allowing us to direct our attention to specific external stimuli?
thalamus
Which structure does NOT have direct neural connections to the cerebellum?
thalamus
The interaction between actin and myosin in smooth muscle requires ________. A) the interaction between calcium and troponin to expose the myosin binding site on the actin molecule B) that the calcium-calmodulin complex activates myosin light-chain kinase, which phosphorylates myosin light chain thereby allowing myosin to bind with actin C) the tropomyosin must be moved out of the way by troponin before myosin can bind to actin D) the activation of troponin, which stimulates myosin light-chain kinase to phosphorylate myosin light chain, allowing myosin to bind with actin E) that the calcium-calmodulin complex directly phosphorylates myosin light chain, allowing myosin to bind to actin
that the calcium-calmodulin complex activates myosin light-chain kinase, which phosphorylates myosin light chain thereby allowing myosin to bind with actin
During isovolumetric relaxation, ________.
the AV and semilunar valves are closed and ventricular pressure is decreasing
What is occurring during ventricular ejection?
the AV valves are closed and the semilunar valves are open as blood is leaving the ventricles
The balance between sympathetic and parasympathetic activity is modified primarily by ________.
the activity of the body
In its active form, a G protein will have ________.
the alpha subunit separated from the gamma and beta subunit
In order for cross-bridge cycling to occur, the actin-myosin complex must be broken by which of the following?
the binding of ATP to myosin
basal nuclei include
the caudate nucleus, the globus pallidus, and the putamen. These structures are involved in modifying movement
The programming and feedback of movement are supported by
the cerebellum, thalamus, basal nuclei, certain brainstem nuclei, and various cortical association areas.
Mobitz type 1 heart block
the electrical signals are delayed more and more with each heartbeat, until the heart skips a beat. On the EKG, the delay is shown as a line (called the PR interval) between the P and QRS waves. The line gets longer and longer until the QRS waves don't follow the next P wave. Sometimes people who have Mobitz type I feel dizzy or have other symptoms. This type of second-degree heart block is less serious than Mobitz type II.
What converts the myosin head into the high-energy state?
the hydrolysis of ATP
The binding of calcium to troponin will directly cause which of the following?
the movement of tropomyosin, thereby exposing the myosin-binding site on the actin molecule
REM characteristics
the muscles controlling face, eyes, and distal limbs frequently twitch. REM sleep demonstrates an overall increase in brain activity compared to SWS sleep, except for the limbic system, where activity decreases during REM sleep. Periodically, breathing is stimulated and sympathetic activity is increased. Heart rate and blood pressure may rise while body temperature control is lost. During REM sleep, dreams are more elaborate and intense and are usually more narrative.
During the cross-bridge cycle, ATP binding to myosin causes which of the following?
the myosin head to detach from actin
Under resting conditions, heart rate is primarily under the control of what control system?
the parasympathetic nervous system
The increase in ventricular volume early in diastole reflects ________.
the passive movement of blood through the atrium and into the ventricle
The shortening of a skeletal muscle fiber during contraction involves which of the following?
the sarcomeres shortening
In active transport, the affinity of the carrier protein for the molecule being transported is greater on which side of the membrane?
the side with the lower concentration
microfilaments
the smallest of the cytoskeletal proteins. The functions of microfilaments, such as actin, include contraction, amoeboidlike movement of cells, and separation of the cytoplasm during cell division. Other microfilaments provide the structural support for the microvilli of cells within the small intestines and hair cells of the cochlea.
The SA node is innervated by ________.
the sympathetic and parasympathetic nervous systems
Hyperglycemia can ultimately lead to activation of ____________ and release of _______________.
the sympathetic nervous system, epinephrine
As skeletal muscle is further stretched beyond the length where optimum force is developed, ________.
the thin filaments are pulled away from one another, thereby reducing their ability to interact with myosin
As the sarcomere length of skeletal muscle is reduced beyond the length where optimum force is developed, ________.
the thin filaments overlap one another, thereby reducing their ability to interact with myosin
biogenic amines
the three catecholamines—dopamine, norepinephrine (noradrenaline), and epinephrine (adrenaline)—and histamine and serotonin
The ability to detect the direction from which a sound originates is determined by ________.
the time delay between that sound reaching the right and left cochlea
The speed with which the skeletal muscle generates force is determined primarily by ________. A) the amount of energy available B) the type of myosin present C) actin D) troponin E) tropomyosin
the type of myosin present
What is the source of variability in the response of smooth muscle cells from different organs to autonomic nervous activity (some relax to sympathetic nervous output while others contract)?
the type of receptor present on the effector organ
Sensitize tissue to insulin, thereby countering the resistance to insulin.
thiazolidinediazones
What medicine for the treatment of diabetes sensitizes tissue to insulin?
thiazolidinediones
What type of neuron in the thalamus communicates sensory information to the cerebral cortex?
third order neurons
The sympathetic nervous system is also called the ________ division of the autonomic nervous system.
thoracolumbar
Elastic fibers that anchor thick filaments in place.
titin
Which of the following is a structural protein that extends along each thick filament from M line to Z line.
titin
When a skeletal muscle is passively stretched, that cell has a tendency to spring back once the force that was stretching the muscle is removed due to ________.
titin acting as a spring using the energy stored by the stretching
Proprioceptors provide the body with continuous information that changes little as a particular joint angle is maintained, and are therefore an example of ________ receptors.
tonic or slowly adapting
A person has damage to the right dorsal columns of the spinal cord at the thoracic level. This person would have impaired ________.
touch sensation of the right leg
What two cytokines released by platelets during hemostasis promote inflammation?
transforming growth factor beta and platelet derived growth factor
The visual system is an excellent example of parallel processing, where visual details are ________.
transmitted along separate pathways to the primary visual cortex where they are then integrated
When bone marrow is transplanted, the primary source of rejection is ________.
transplanted lymphocytes initiating an immune response to the host
The continuation of the sarcolemma that penetrates the interior of the muscle fiber and thereby facilitates the release of calcium from the sarcoplasmic reticulum is called what?
transverse tubule
Contains DHP receptors
transverse tubules
A muscle is stimulated at a frequency that allows the muscle to relax completely between contractions. However, the amount of tension increases with each contraction. What is this called?
treppe
What is the protein component of the thin filament that blocks the myosin-binding site on the actin monomer?
tropomyosin
Troponin is a complex of three proteins that bind to ________, ________, and ________.
tropomyosin, calcium, and actin
7) What is the protein component of the thin filament that binds to calcium thereby initiating skeletal muscle contraction?
troponin
Binds calcium in cardiac muscle cells.
troponin
Binds calcium in skeletal muscle cells.
troponin
What structure separates the middle from the external ear?
tympanic membrane
Sound waves traveling through the air initiate a vibration of the ________. The sound waves are then transmitted along the ________ to the cochlea.
tympanic membrane, ossicles
Caused by damage to beta cells of the pancreas
type 1
What is dysthesia?
unpleasant sensation produced by innocuous stimuli
The cranial nerve that innervates most of the viscera in the thoracic and abdominal cavities is the ________.
vagus nerve
Postganglionic neurons of the autonomic nervous system release neurotransmitter from
varicosities
What are swellings of postganglionic autonomic axons from which neurotransmitters are released called?
varicosities
Sympathetic preganglionic neurons exit the spinal cord via the (dorsal / ventral) root, and then join the spinal nerve. They leave the spinal nerve and enter the ganglion via the (gray / white) ramus. Most of the postganglionic fibers return to the spinal nerve via the (gray / white) ramus.
ventral : white : gray
Where are the cell bodies of efferent neurons located?
ventral horn
Where do lower motor neurons originate?
ventral horn of the spinal cord
What are hollow cavities within the brain that are bathed by cerebrospinal fluid?
ventricles
Where is cerebrospinal fluid synthesized?
ventricles
Which of the following structures is POORLY innervated by the parasympathetic nervous system, therefore, an increase in parasympathetic activity has little effect on this structure?
ventricles
Afferent neurons from the semicircular canal, the utricle, and the saccule enter the brainstem where most terminate within the ________.
vestibular nuclei
Autonomic reflexes are also called ________ reflexes.
visceral
The presence of ________ within varicosities mediate the release of neurotransmitter.
voltage-gated Ca2+ channels
What is a microaneurysm?
weak bulges in the walls of small blood vessels
Sympathetic preganglionic neurons exit the spinal nerve via the ________ before they enter the ________.
white ramus : ganglion of the sympathetic trunk
Which of the following is NOT a visceral reflex? A) pupillary light reflex B) withdrawal reflex C) vomiting D) urination E) swallowing
withdrawal reflex
Which of the following best describes the location of the anterior segment?
within the eye, between the cornea and lens
Strands of connective tissue that connect the lens to muscles for accommodation.
zonular fibers