Biology by THEO
stratum lucidum
a layer of the epidermis found only in the thick, hairless skin of the fingers, palms, and soles
lacteal
a lymph tubule located in the villus that absorbs fatty acids
Isotype switching
cells can change which isotope of antibody they produce when stimulated by specific cytokines antibodies come in 5 different isotopes: IgM, IgD, IgG, IgE, and IgA diff types used at different times no diff pathogens
what causes hair to stand up
arrector pilli muscle
blood pressure drops from the ______ to _____ circulation. With the largest drop across the _____.
arterial --> venous arterioles
What form do the main energy sources have to be in to be absorbed?
carbohydrates--> monomers proteins--> di or tri peptides or monomers lipids--->?
gastric juice
combination of secretions from chief and parietal cells contains: -->pepsinogen /pepsin from the chief cells --->HCl from the parietal cells that cleaves the pepsinogen to pepsin and secrete intrinsic factor
bones strength comes from
compact bone
The outermost portion of bone are composed of _______ whereas the internal core is made of _______
compact bone spongy bone
abductor muscle
moves limb away from midline of body ex: deltoid
In skeletal muscle, contraction starts at the ________
neuromuscular junction
rectum function
storage site for feces
Meissner's corpuscles
light touch receptors (located in dermis)
What can a spirometry measure
parameters measured in spirometry are Vital capacity (VC), Forced vital capacity (FVC), Forced expiratory volume (FEV) Tidal volume(TV) Can NOT be measured: -residual volume (RV) -total lung capacity
cytoplasmic inheritance
transmission of genetic material independent of the nucleus -ex: mitocondria -also called extranuclear inheritance
Skeletal muscle is responsible for ____ movement and is therefore innervated by the ________ nervous system
voluntary ->somatic nervous sytem
emesis
vomiting -->the reversal of peristalsis
divergent evolution
when two or more species sharing a common ancestor become more different over time ex: seals and cats
punctuated equilibrium model (of evolution)
Changes in some species occurs in rapid bursts rather than over evenly overtime -->was derived based on examining the fossil record
piloerection
Condition of the hair standing straight up occurs when we're cold --> traps layer of heated air near skin
flexor muscle
Decreases the angle across a joint (bends a limb at a joint) ex: biceps brachii
Z-line
Defines the boundary between each sarcomere
two groups are considered separate species when
isolation occurs -->progeny of the populations can no longer freely interbreed
The fluid in the Bowman's capsule is _____ to plasma
isotonic -->so salt can leave from the glomerulus with out any active transport
At the begining of the loop of henle the filtrate is ____ to the interstitium and at the end of the lopp of henle the filtrate is ____
isotonic ---> hypotonic -so there is a slight degree of dilution -->also volume of filtrate has been significantly reduced
Maltase
A digestive enzyme that breaks maltose into glucose. ->brush boarder enzyme
alleles
Different forms of a gene -->each gene may have alternative forms
Anatomy of the stomach (11 terms)
(except body should be labeled up above the opening - near the fundus)
transposons
(jumping genes) short strands of DNA capable of moving from one location to another within a cell's genetic material -can insert or remove themselves fro the genome -seen in both prokaryotes and eukaryotes
hydrostatic pressure
- force per unit area that blood exerts against the vessel walls - generated by contraction of heart and elasticity of arteries -pushes fluid out of the vessels (when greater than oncotic pressure)
Path of bile from gall bladder
**CCK released** gall bladder contracts and pushes out bile ---> cystic duct ---> common bile duct ---> duodenum
sarcomeres that are attached end to end form a ____
myofibril
G1 Stage
- "presynthetic gap" - cells create organelles for energy and protein production, while also increasing their size -can't pass into S phase unless they meet the criteria to pass the "restriction point " -ex: need correct complement of DNA
Hypersensitivity reactions
- A family of immune reactions including allergies and autoimmunity. -when the body either reacts to self or overreacts to something that is not dangerous like peanuts or pollen
Viral genomes
- Either DNA or RNA genomes - Some circular, but most linear Single-stranded RNA viruses -can be positive sense or negative sense: >positive sense= genome can be directly translated into functional proteins by the host ribosomes >negative sense= the negative sense RNA virus acts as a template for a complementary strand which is then used as a template for protein synthesis *must carry an RNA replicase to ensure that complementary strand is replicated
Telophase I
-A nuclear membrane forms around each new nucleus -at this point each chromosome consists of two sister chromatids -cells are now haploid (n) -23 chromosomes in each daughter cell
modern synthesis model of evolution
- neo-darwinism - account for mutation and recombination as mechanisms of variation and considers differential reproduction to be the mechanism for reproductive success
sarcolema
- plasma membrane of muscle cells; -can propagate action potential i. Invaginated by T-tubules- channels for ion flow ii. Wraps several myofibrils together to form a muscle cell/muscle fiber
Where is smooth muscle found?
- respiratory tree - reproductive system - blood vessel walls - uterus - digestive tract - bladder
What starts the cascade that leads to blood clotting
--> Collagen and tissue factor are exposed to platelets and coagulation factor
How does the autonomic nervous system regulate the digestive system?
--> Parasympathetic: -stimulates digestive activities -increases secretion form exocrine glands -promotes peristalsis -->sympathetic: -inhibits digestive activities -slows gut motility -decreases blood flow to the digestive system
What happens if a women is Rh- and her fetus is Rh+
--> She will become sensitive to the Rh factor but will only start to make antibodies against it once the first child has already been born -->so it only becomes an issue if her second child is also Rh+ --->maternal anti-Rh+ antibodies will cross placenta and attack baby condition: erthyroblastosis fetalis
How does the skin help to maintain the blood osmolarity
--> keeps water from entering from outside -->keeps water from leaving from the tissues -->why burn victims that have lost lots of skin have risk of being dehydrated through their tissues
The dorsal root ganglia contains cell bodies of ________ neurons
--> only sensory neurons !!
what could happen if the ureter is obstructed by a kidney stone
--> pressure would build up and could be to the point where hydrostatic pressure in bowman's capsule is higher than in blood so blood no longer passes into nephron to be filtered
At what point in the heart's electrical pathway does the signal delay?
-->At the AV node The signal is delayed here to let the ventricles fill up completely before their contraction
Vitamin K role in clotting
-->Needed to add Ca2+ to thrombin so it is activated -also assists with other clotting factors but that is beyond scope of MCAT
The SA node causes the atria to contract which is responsible for
-->The atrial kick which causes even more blood to get pushed into the ventricles than would have occurred passively (from the blood flowing into the relaxed ventricles) ->atrial kick is responsible for 5-30% of cardiac output
Which has higher blood pressure: the superior vena cava or the aorta?
-->aorta bc the left ventricle is much more muscular and has a stronger force when it pumps blood
Starling forces
-->balance of the opposing hydrostatic and oncotic pressures -maintains proper fluid volumes & solute concentrations inside & outside the vasculature -Imbalance of these pressures results in too little or too much fluid in tissues
What is bodies response when no leptin?
-->body responds as if in starvation mode bc nothing to tell body that its is full result: -elevated plasma cortisol -inability to effectively undergo thermogenesis -unrestrained appetite -resistance to insulin
Diet heavy in meat would cause increase in ___ in your urine
-->higher amount of nitrogen in blood (can disrupt pH of blood) --> liver converts the ammonia to urea --> urea travels to kidneys and is excreted into the nephron for excretion in urine -->urine has higher amount of urea
What does it mean that cardiac muscle has myogenic activity
-->means that it generates an impulse with out external input from the nervous system -Although the nervous system does control the rate of the heart beat (slow when relaxed or fast when scared) it is not responsible for generating the heat beat itself
Evolution is not equivalent to natural selection bc
-->natural selection is just a mechanism of evolution evolution can occur in other ways without natural selection present
Adaptive radiation
-->rapid rise in the number of different species from a common ancestor -favored by environmental changes or the creation of new niches for species to occupy -favored by isolation of small groups of ancestral species
What is the value that needs to be reached to cause an action potential?
-55 to -40 mV -need to get the membrane depolarized enough by excitatory signals to do this
Resting potential in a neuron
-70mV >This is created by potassium ions moving out of the cell while sodium ions move into the cell. >Pumps (Na+/K+ ATPase) are pumping potassium into the cell so the concentration gradient makes it so potassium wants to leave the cell. Potassium leak channels allow potassium out of the cell. But when too much K+ gets out it is drawn back in by the negative charge inside the cell. Overall the potassium equilibrium potential is -90mV. It is negative because a positive ion is leaving the cell. >These same pumps are pumping Na out of the cell. Therefore Na wants to get into the cell and does so thro sodium leak channels. The equilibrium potential of sodium is around 60 mV (positive because a positive ion is entering the cell). >These two values average out to -70mV. This is closer to potassium's equilibrium potential because the cell is slightly more permeable to K+.
How do amino acids and carbs get from cell of small intestine into the circulatory system
->blood is constantly passing by the epithelial cells carrying away the nutrients so the area inside the cell always has a higher concentration of carbs and AAs than the blood outside >Therefore, simple carbs and AAs diffuse from the epithelial cells into the capillaries
Fertilization Steps
-A secondary oocyte is ovulated(released) from the follicle around day 14 of the menstrual cycle -The secondary oocyte travels to the fallopian tube where it can be fertilized up to 24 hours after ovulation -fertilization usually occurs in the widest part of the fallopian tube called the ampulla >When the sperm meets the secondary oocyte it binds it and releases acrosomal enzymes that let enable the head to penetrate the corona radiata and zone pellicuda -The first sperm to penetrate forms a tubelike structure known as the acrosomal apparatus, which extends to and penetrates the cell membrane -its pronucleus may then enter the egg once it has finished meiosis 2 >After penetration of the sperm thro the cell membrane the cortical reaction takes place: -a release of Ca2+ ions occurs -these Ca2+ ions depolarize the cell so no the sperm can bind -and they help increase the metabolic activity of the zygote -the membrane of the zygote is now called the fertilization membrane.
How does relaxation of skeletal muscle occur?
-Acetylcholine is degraded in the synapse by acetylcholinesterase -sarcolema repolarizes -SR takes up Ca from the sarcoplasm -ATP bind myosin head and frees them from actin -the sarcomere returns to original width and the myosin binding sites are covered up bc no Ca2+ available to make tropomyosin move
Somatostatin
-An inhibitor of both insulin and glucagon -secreted by delta cells of the pancreas in response to high levels of glucose and amino acids in the blood ->also produced by the hypothalamus. There it decreases the secretion of growth hormone and also has same effects on insulin and glucagon
cecum
-An outpocketing that accepts fluid that is exiting the small intestine thro the ileocecal valve and is the site of the attachment of the appendix -also home to some aerobic bacteria
epididymis, vas deferens, ejaculatory duct, urethra
-As sperm are formed they are passed to the epididymis, where their flagella gain motility -they are stored there until ejaculation -during ejaculation sperm travel through the vas deferent into the ejaculatory duct at the posterior edge of the prostate gland -the two ejaculatory ducts (right and left) then fuse to form the urethra--> carries sperm thro penis as it exits the body
S Stage
-DNA replication occurs -a single chromatid replicates to form two chromatids connected by a centromere -note that even tho this happened the ploidy of the cell did not change -still only 46 chromosomes present even though 92 chromatids are present
The speed at which action potential move depends on what characteristics of the axon
-Axon's length and cross sectional area -longer = increased resistance and slower conduction -Greater cross-sectional area= decreased resistance and faster propagation ** cross-sectional area matters more --> also myelin increases the speed bc signal can jump between nodes of ranvier = saltatory conduction
B-cell activation
-B-cells that have not yet encountered an antigen are naive and not activated -these B-cells wait in the lymph nodes for antigen to be presented to them -upon exposure to the correct antigen the B-cell proliferates and produces two types of cells: 1)plasma cells: produce large amounts of antibody and die off eventually 2)memory B-cells: stay in the lymph node and wait for re-exposure to the antigen initial activation take 7-10 days --> primary response When microbe is encountered again the memory cells jump into action and produce antibody specific to the pathogen --> secondary response (faster + better)
Example of the steps in an immune response to an extracellular pathogen
-Bacteria are introduced into body -macrophages (and other APCs) engulf the bacteria and release inflammatory mediators (cytokines) -They present antigen on surface with MHC II -The cytokines attract more immune cells like neutrophils -mast cells are activated by the inflammation and degranulate releasing histamine which causes capillaries to be leaky -Dendritic cell leaves and goes to nearest lymph node and presents the antigen to a B-cell that matches (clonal selection) -the B-cell creates plasma cells and memory cells -Antibodies travel thro blood and tag the antigen for destruction -Dedeitic cells also present the antigen to T-cells and activate a T-cell response -CD4+ T-cells are activated (helper t-cells) two types i) TH1 cells release interferon gamma which activates macrophages and increases their ability to kill bacteria ii)TH2 help activate B-cells **Memory B-cells and T-cells remain
Why do we get the AB blood type
-Bc the A and B surface proteins are codominant -so you can get one if you only have one allele or both if you have both alleles or none if you don't have either (type O)
T-cells versus B-cells
-Both cell types develop in the bone marrow -But B-cells also mature there and are then activated in the spleen or lymph nodes -T-cels mature in the thymus -B-cells role is to produce antibodies and they are part of the humoral immune system -T-cells role is to coordinate the immune system and to carry out direct kills on specified cells -T-cells are part of the cell-mediated immune system (branch of the adaptive immune system)
Tidal Volume (TV)
volume of air inhaled or exhaled in a normal breath
Metaphase II
-Chromosomes line up on the metaphase plate
immovable joints
-Consist of bones that are fused together to form sutures or similar fibrous joints. -Found primarily in the head, where they anchor bones of the skull together.
The nucleus
-Control center of the cell -surrounded by a nuclear envelope which is a double membrane that keeps it as a separate environment from the rest of the cell -nuclear pores allow selective two-way exchange btw material in cytoplasm and nucleus -contains DNA that is wound around organizing proteins called histones which are further fond into chromosomes >there is a subsection of the nucleus known as the nucleolus. It is where ribosomal RNA (rRNA) is synthesized.
Somatic nervous system
-Controls voluntary movements of the PNS -Division of the PNS that controls the body's skeletal muscles. -consists of sensory and motor neurons distributed through out the skin and joints and muscles.
Increased stiffness in the lungs would cause?
-Decreased total lung capacity -decreased inspiratory reserve volume -decrease residual volume
The menstrual cycle summary four phases
-During reproductive years estrogen and progesterone rise and fall in a cyclic pattern -In response the endometrial lining grows and sheds in menstrual cycle -four phases: follicular, ovulation, the luteal, and menstruation
The menstrual cycle: the ovulation phase
-Even tho estrogen causes negative feedback on LH and FSH, once it gets above a certain level it actually increases their levels ->positive feedback! -during this phase the estrogen reaches that threshold level and causes release of GnRH and LH and FSH -the surge in LH induces ovulation: the release of the ovum from the ovary into the abdominal cavity!!! >the ruptured ovarian follicle releases the an oocyte into the abdominal cavity close to the entrance of the fallopian tube. With the aid of beating cilia, the oocyte is drawn into the fallopian tube, through which it travels until it reaches the uterus.
Female reproductive anatomy
-Female gonads = ovaries -The ovaries produce estrogen and progesterone -ovaries are located in the pelvic cavity -each ovary consists of thousands of follicles -follicles are multilayered sacs that contain the eggs(Ova) and nourish them -Between puberty and menopause one egg per month is ovulated into the peritoneal sac -the egg is then drawn into the fallopian tube of oviduct which is lined with cilia that propel the egg forward -fallopian tubes are connected to the uterus which is where fetus development occurs -lower part of uterus is called the cervix -cervix connects to the vaginal canal -external female anatomy = vulva
Genotype vs. Phenotype
-Genotype : the genetic combination possessed by a person -Phenotype : the manifestation of a given genotype as an observable trait
How do neurotransmitters receptors tell us if a NT is excitatory or inhibitory
-If the NT has a receptor that is a ligand gated it will cause the cell to be either hyperpolarized(inhibited) or depolarized (excited) -If the NT receptor is a G protein coupled receptor it will cause either changes in the level of cyclicAMP(cAMP) or an influx of calcium.
What cause a right shift on the oxyhemoglobin curve?
-Increased partial pressure of CO2 -increased H+ (decreased pH) -increased temperature -increased 2,3-BPG (side product of glycolysis)
What is unique about cardiac muscle cells
-Intercalated discs connect the cardiac muscle cells and contain many gap junctions -These gap junctions allows for the free flow of ions btw the cells -this allows for rapid and coordinated depolarization of muscle cells and efficient contraction of cardiac muscle
How does the body react to high pH?
-It the blood is too basic the chemoreceptors will sense this and the ventilation center in the brain will slow the respiratory rate -This will cause CO2 to be retained -This will shift the bicarbonate buffer system to be shifted right -This means more H+ will be produced --> lowering the blood pH!
M stage
-Mitosis -divided into four phases: prophase, metaphase, anaphase, telophase -ends with cytokinesis (part of M phase but not part of mitosis?)
How is the respiratory system involved in thermoregulation
-Nasal and tracheal capillaries can expand (vasodilation) to let more heat be disapaited -or they can constrict (vasoconstriction) to conserve thermal energy -however this is mostly a function of the capillaries in the skin and also of using sweat glands in the skin to cool off -The respiratory system can also transfer heat to the environment through the evaporation of water in mucous secretions
Natural selection (tenets that darwin laid out)
-Organisms produce offspring, of which only some survive to reproductive maturity -chance variations in a population may be heritable. If these variations give organism and advantage they are called favorable -individuals with more of these favorable variations are more likely to survive to reproduction age and produce offspring -->have greater fitness
Mitochondria
-Powerhouse of the cell -two membranes: the outer serves as a barrier, the inner folds onto itself in structures called cristae that hold the ETC -the matrix is the area inside the inner membrane -protons are pumped from the matrix into the intermembrane space to establish the proton motive force. -These protons flow thro ATPsynthase to generate ATP during oxidative phosphorylation -they contain their own genes and replicate via binary fission -mDNA is 1 circular chromosome, double stranded -example of cytoplasmic inheritance -thought to have originated from an engulfing on an aerobic prokaryote by an anaerobic prokaryote -They also are capable of killing the cell thro release of enzymes from the ETC to start apoptosis
Erythrocyte Life Cycle
-Produced in bone marrow -Live for 120 days in blood -then they are phagocytocized in the liver or spleen
two types of arteries that contain deoxygenated blood
-Pulmonary and umbilical arteries
Renal portal system
-Renal artery passes into the medulla of the kidney and enter the cortex as the afferent arterioles -The highly convoluted capillary tufts made up of the afferent arterioles are known as glomeruli -after blood basses through the glomerulus, the efferent arterioles pass downwards and surround the loop of henle, forming a second capillary bed known as vasa recta
What is reabsorbed and or secreted in the Distal convoluted tubule (DCT)
-Salt is reabsorbed (leaves) and water follows it out (concentrating the urine) -responds to aldosterone -secreted (enters it): H+, Urea, NH3, urea
Anterior pituitary hormone products
-Synthesizes seven different products (4 tropic, 3 direct) Tropic hormones: 1) Follicle stimulating hormone (FSH)--> acts on gonads [caused to be released by GnRH] 2) Luteinizing hormone(LH) --> acts on gonads [caused to be released by GnRH] 3) adrenocorticotropic hormone (ACTH) --> acts on adrenal cortex [caused to be released by CRF] 4) Thyroid stimulating hormone (TSH) --> acts on thyroid [caused to be released by TRH] Direct hormones: 5) prolactin --> acts on mammary glands to cause then to produce milk [caused to be released by hypothalamus NOT releasing Prolactin inhibiting factor (dopamine)] 6) Endorphins --> decreases the body perception of pain [released after you exercise for a when you are feeling pain] 7) Growth Hormone --> acts on tissues that are not growing and prevents their uptake of glucose and promotes breakdown of FAs, this frees up energy stores so muscles and bones can grow. [released in response to GHRH]
Anaphase
-The centromeres split so each chromatid has its own distinct centromere -sister chromatids separate -the Microtubules shorted allowing the sister chromatids to be pulled closer to their respective poles
Exhalation steps
-The diaphragm relaxes and (if active) the internal intercostals and abdominal muscles contract -this causes decrease in the volume of the chest cavity -this increases the pressure in the intrapleural cavity and so also the lungs -The air flows out of the high pressure lungs into the lower pressure environment
What does the fetus rely on from the mother
-The fetus's lungs are not functioning yet so it relies on oxygenated blood from the mother -->also helps that fetal hemoglobin has a higher affinity for oxygen than the maternal hemoglobin -fetus also gets nutrients from the placenta -also antibodies are passed placental membrane and serve a protective function bc the fetus is immunologically naive -also the liver doesn't function so sends its waste and toxins to mother to be detoxified in her liver
Female sexual development
-The ovaries are under the control of LH and FSH secreted from the anterior pituitary -they secrete estrogen and progesterone Estrogen -secreted in response to FSH -causes the development of the female reproductive system -causes female secondary sexual characteristics (breasts, wider hips, fat distribution) -In embryo estrogen stimulates the development of the female reproductive tract -in adults estrogen leads to thickening of the lining of the uterus (endometrium) each month Progesterone -secreted by the corpus luteum (the remains of the ovarian follicle following ovulation) in response to LH -helps with development and maintenance of the endometrium (not thickening, estrogen does this) -By end of first trimester in pregnancy, progesterone is supplied by the placenta while corpus luteum atrophies
Male reproductive anatomy
-The primitive gonads develop into the testes -Testes have two functional units: the seminiferous tubules and the interstitial cells of leydig >seminiferous tubules -sperm are produced here -nourished here by the sertoli cells >interstitial cells of Leydig -secrete testosterone and other male hormones (androgens) -The testes are located in the scrotum, an external pouch >works to keep the sperm at temp 2-4 C lower than the body's temp -->muscle around the vas defers can raise and lower the testis to maintain the proper temperature for sperm development
What are the direction and the contents of the umbilical vein and umbilical arteries
-The umbilical arteries carry deoxygenated blood away from the fetus and to the placenta where they exchange this blood and other toxins. The Uterine vein takes these away. -The umbilical vein takes the nutrients and oxygen from the uterine artery from the placenta to the fetus **good way to remember this is that away from heart is the artery so the umbilical artery is going away from the heart of the fetus and picking up oxygen at the placenta. And the vein is coming back to the heard with oxygen from mother to be pumped to rest of body. Or just know that the oxygenation levels in the arteries and veins of the fetus is opposite that to the mother
What stimulates the development of blood platelets ?
-They are produced in bone marrow by process called hematopoiesis (production of both blood cells and platelets) -thrombopoietinis a hormone that is secreted by the liver and the kidney which causes the production of megakaryocytes which then make platelets hematopoietic stem cell ---> myeloid stem cell --------(thrombopoietin)---> megakaryocyte ---> platelets
Why are arteries more muscular and more elastic than veins?
-They are thicker and more muscular to withstand the higher pressure placed on them -Additionally they are elastic so that when the heart goes into diastole they can continue to generate blood pressure from their elastic recoil to push blood forward
Thymosin
-Thymus releases this -helps with T-cell development and differentiation -thymus atrophies when you are an adult, so thymosin levels drop as you age
endocrine control over basal metabolic rate
-Thyroid secretes Triiodothyronine(T3) and thyroxine (T4) -these hormones are amino acid tyrosine with iodines added on -they work by making the energy production more or less efficient -also alter the utilization of glucose and fatty acids -increased T3 and T4 lead to increased cellular respiration which then increases protein and fatty acid turnover -high levels of them act as negative feedback and suppress TSH and TRH synthesis
Birth
-Vaginal birth is also known as paturition -accomplished by rhythmic contractions of the uterine smooth muscle -coordinated by prostaglandins -and peptide hormone oxycontin plays a role >consists of three phases: i)cervix thins and amniotic sac ruptures (water breaks) ii)strong uterine contractions coordinated by prostaglandins and oxycontin result in birth of fetus iii)afterbirth -placenta and umbilical chord are expelled
Water absorbed in the small intestine
-Water is drawn in with with the solutes that are absorbed and enters blood stream -water passes both transcellularly (across cell membrane) and paracellularly (squeezing btw cells) to enter the blood
How is the action potential propagated?
-When enough excitatory signals reach the axon hillux, it results in depolarization of about -55 mV -This depolarization results in voltage gated Na+ channels opening up and letting Na+ flow into the neuron -This is driven by both the electric gradient and concentration gradient -This increase in the membrane potential opens up voltage channels next to it, moving down the axon -also once a Na+ channel has been opened for a certain amount of time it then closes and can't be reopened for a period called the refractory period -That is why the action potential only travels in one direction down the axon -after this the efflux of K+ overshoots and causes a hyperpolarization of the neuron
Shape of hemoglobin molecule that increases binding vs shape that increases release
-When one binds changes the conformation from taut (T) to relaxed (R) --> the R conformation much more easily takes on oxygen molecules -When one leaves changes from R to T (a bit) and as more leave gets easier for another to leave as conformation changes more and more to T state.
What mechanism causes neurotrasmiters to be released into the cleft?
-When the action potential reaches the nerve terminal, voltage gated calcium channels open up and calcium floods into the cell -This influx of calcium triggers the vesicles that are storing the NTs to fuse with the membrane of the cell and release the NTs via exocytosis into the cleft -NTs diffuse across cleft and bind with receptors on the post synaptic membrane
Antibody shape and domains
-Y shaped molecules with two identical light chains and two heavy chains -chains linked by disulfide bonds -each chain has an antigen binding region which is called the variable region and is at the tip of the Y -This region will bind only one antigen region (epitope) -B-cells undergo hypermutation of their antigen binding region trying to find the best match for antigen (takes a while) -remaining part of antibody is the constant region -this is the part of the antibody that NKCs and macrophages bind to and initiate the complement cascade
Two types of refractory periods
-absolute refractory period: No amount of stimulation can cause another action potential to occur -relative refractory period: There must be a greater than normal stimulation to cause an action potential to occur. Because the membrane is starting from a potential that is more negative than its resting value.
Vitamin D effects on bone
-activated by PTH -promotes bone reabsorption so that new, stonier bone can be rebuilt in the old bones place
When antigen binds an antibody on the surface of a B-cell it causes
-activates the B-cell -causes proliferation and formation of plasma and memory cells --->only B-cells that bind an antigen with high affinity survive (clonal selection)
What are the two capillary beds in the renal portal system
-afferent arterioles make up the glomeruli -efferent arterioles forming the vasa recta
The menstrual cycle: the luteal phase
-after ovulation, LH causes the ruptured follicle to form the corpus luteum, which secretes progesterone -progesterone maintains the lining for implantation -estrogen levels are also high -high levels of progesterone inhibit GnRH, FSH, and LH which prevents ovulation of multiple eggs
Peptide hormes
-all derived from larger polypeptide precursors that are cleaved during post translational modification in the ER. -then sent to golgi to be activated and then secreted from cell via exocytosis -They can not pass thro plasma membrane so must bind to receptor at cell surface -they are considered first messengers -activate second messengers that lead to a signaling cascade -amplification is present at each step -rapid but short lived effects -do not require carrier molecules to get to targets -ex: ADH and insulin -bind G-protein coupled receptors
Bacteria
-all have a cell membrane and cytoplasm -some have flagella -but bacterial flagella are different from eukaryotic flagella -also have significantly smaller ribosomes -no nucleus, unicellular, no membrane bound organelles, single circular DNA (double stranded!) -some are mutualistic symbioses to humans (ex: bacteria that makes vitamin K and biotin) -some are pathogens and parasites -can live intracellularly or extracellularly Classified by shape: -spherical --> cocci -rod-shaped --> bacilli -spiral shaped --> spirilli **part of prokaryotic category
movable joints
-allow bones to shift relative to each other -ex: >ball and socket joint (shoulder and hip) >hinge joints (elbow or knee) -these joints are strengthened by ligaments (connect bone to bone) -consist of a synovial capsule that encloses the joint cavity -also has a layer of soft tissue called synovium that secretes synovial fluid for joint lubrication -and articular cartilage coats the articular surface of bone so feel less impact
cortical sex hormones
-androgens and estrogens - made by adrenal cortex -Males secrete a lot of androgens in testes so adrenal testosterone plays a small role (excess would result in no noticeable difference in male infant) - excess androgen production in females leads to masculinized genitalia -excess estrogen production in a male would lead to feminineization of male sex organs
cell to cell communication: inducers
-are often growth factors which are peptides that promote differentiation and mitosis in certain tissues -often only act on specific cell types or in certain areas -ex: pax6 is secreted from ectoderm in the head to cause the lens to develop -lens then triggers optic vesicles to make optic cup which becomes the retina -this is an example of reciprocal development Signaling often occurs via gradients -morphogens diffuse through out the cell ex morphogens: TGFbeta, sonic hedge hog and epidermal growth factor
conjugation
-bacterial form of sexual reproduction -two cells form a bridge and one transfers genetic material to the other -the donor male (+) transfers to the recipient female (-) -the bridge is made by an appendage known as the sex pili that is from the donor male -the sex pili can only be made by bacteria that contain a plasmid known as a sex factor (has the genes to make a pilus) ex of a sex factor is the F factor in E.Coli -bacteria with the F factor are F+ and bacteria with out it are F- -during conjugation the F+ cell replicates its F factor and donates a copy to the F- cell so it is now a F+ cell -usually only the plasmid is transferred across the bridge during conjugation -but sometimes the plasmid itself can get integrated into the bacterias genome, like when it is picked up via transformation -in this case when a bacteria with the sex factor in its genome formed a bridge to carry out conjugation, the whole genome is attempted to be transferred bc the plasmid is within there!! -however the bridge usually breaks before the whole genome is moved into new bacteria -cells that have the sex factor in their genome are called high frequency recombination cells or Her cells.
Transduction
-bacterial genetic recombination that requires a vector -vector= a virus that carries genetic material from one bacterium to another -bacteriophages (viruses that infect bacteria) can accidentally incorporate host DNA when it infects a bacteria -then when it goes to infect another bacteria it releases DNA from the original host bacterium -this DNA can integrate into the genome of the new host
blood pressure regulation via vasoconstriction
-baroreceptors in the walls of the vasculature -these are specialized neurons that sense changes in mechanical forces on the walls -can stimulate sympathetic nervous system to constrict the vessels to increase the blood pressure
The menstrual cycle: the follicular phase
-begins when the menstrual flow begins--> shedding from the lining of previous cycle -GnRH secretion from hypothalamus increases in response to low estrogen and progesterone concentrations (bc fall off at end of cycle) -The higher GnRH causes release of FSH and LH which develop the ovarian follicles -the follicles produce estrogen which then has negative feed back on the GnRH, LH, and FSH -estrogen stimulates regrowth of the endometrium lining -stimulates vascularization and glandularization of the decidua (uterine lining)
how does shivering help us warm up
-burns lots of ATP in the skeletal muscles -that ATP is converted to thermal energy
G1/S checkpoint
-called the restriction point -The cell determines if the condition of the DNA in the cell is good enough for synthesis (S phase) -if there is damage to the DNA then the cell cycle goes into arrest until the DNA is repaired -protein that controls this = p53
Anaphase II
-centromeres divide -seperating the chromosomes into sister chromatids -23 chromosomes -->46 sister chromatids -23 sister chromatids to each daughter cell
stratum spinosum
-cell layer where keratinocytes become connected to each other -also where langerhan cells are found
Cell migration in cell differentiation
-cells have to get to their correct location to carry out their function -ex: anterior pituitary originates in the oral ectoderm --> has to migrate to location on top of hypothalamus -neural crest cells also have to migrate far and wide thro body
Interferons
-cells that are infected with a virus produce these proteins that prevent viral replication -makes the nearby cells decrease production of proteins -also decreases permeability of close cells -up regulate MHC class I and II proteins so the cells nearby have increased antigen presentation -cause flu-like symptoms such as tiredness and muscle soreness and fever
Stem cells
-cells that have not yet differentiated = stem cells -Cells up to the 16-cell embryo stage are totipotent stem cells bc can become anything -cells in three germ layers are pluripotent-> can be any cell type other than the placenta -cells continue to specialize and are multipotent -> can differentiate into many different types of cells within a particular group ex: hematopoietic stem cells can differentiate into any of the blood cells
melanocytes
-cells that produce melanin -melanin is a pigment that protects skin from UV radiation -once produced the pigment is transferred in to keratinocytes -present in the stratum basale
Metaphase
-centriole pairs are now at opposite ends of the cell -the kinetochore microtubules work with the fibers of the spindle apparatus to align the chromosomes at the metaphase plate
G2/M checkpoint
-check to make sure the organelles are replicated and the cell is the correct size -also that DNA has been replicated properly -p53 plays a role in this check point
How does the body react to low blood pH?
-chemoreceptors just outside the blood brain barrier send signals to brain to increase the respiratory rate -Also the increase in H+ will cause a shift left in the bicarbonate buffer equation which will generate more CO2. This will also be sensed by chemoreceptors and tell the brain to increase respiratory rate -This expulsion of CO2 causes a loss from the left side of the equation which will cause the equation to shift left -In turn more H+ will be lost --> Raising the pH!
bacterial flagella
-composed of a filament, basal body and a hook -filament = hollow helical structure composed of flagellin -basal body is a complex structure that anchors the flagella and is the motor of the flagella -hook connects the filament and the basal body so that the filament rotates
Peroxisomes
-contain hydrogen peroxide -breakdown long chain fatty acids via beta oxidation -help synthesize phospholipids -contain some of the enzymes involved in the pentose phosphate pathway
Prokaryotes
-contain the domains of life: Bacteria and Archaea -have on nucleus -have no membrane bound organelles -have one circular DNA (in nucleoid region) -use the cell membrane for the ETC (bc haven mitochondria) -have a primitive cytoskeleton
Human gestation: third trimester
-continued rapid growth and brain development -increase in the number of antibodies transported from the mother to the fetus, especially during the final month -then growth rate slows and fetus becomes less active because has less room to move
thyroid endocrine function
-controlled by thyroid stimulating hormone (from ant pit) -on front of trachea two main functions: i)setting basal metabolic rate (thro T3 &T4) ii)promoting calcium homeostasis (thro calcitonin)
Enteropeptidase
-converts trypsinogen (pancreas protease) to trypsin --->trypsin then initiates an activation cascade -also activates procarboxypeptidases A and B into their active forms **ETP is an enzyme secreted by the duodenum
epithlial tissue
-covers the body and lines its cavities and protects from pathogens -cells are tightly joined to each other and to the basement membrane (underlying layer of connective tissue) -in most organs makes up the parenchyma (the functional parts of the organ) ex: nephrons in kidney, hepatocytes in liver, and acid producing cells in the stomach -often polarized cells classification: ~based on layers~ -simple epithelia=one layer of cells -stratified epithelia= many layers -pseudostratified= appear to have many layers due to differences in height but actually one layer ~based on shape~ -cuboidal= cube-shaped -columnar= long and thin -squamous= flat and scale like
countercurrent multiplier system in the kidney
-created by vasa recta and nephron flowing opposite directions -bc flow in opposite directions the filtrate is constantly being exposed to hypertonic blood which allows for maximum reabsorption of water
What are the two supplemental energy reserves in muscle
-creatine phosphate can be combined with ADP to form ATP -myoglobin stores oxygen to keep aerobic respiration going
What cause a left shift on the oxyhemoglobin curve?
-decreased temperature -increased pH -decreased H+ -decreased 2,3-BPG -decreased Pa CO2 -HbF (fetal hemoglobin)
amino acid derivative hormones
-derived from 1 or 2 amino acids w/ additional modifications -Include epinephrine, norepinephrine, triiodothyronine, and thyroxine -less predictable behavior so just have to memorize: -Catecholamines (epinephrine and norepinephrine) bind to G protein coupled receptors --> fast onset & short lived -Thyroid hormones bind intracellularly (slower onset & longer duration) -Have names that end in -in or -ine (thyroxine)
Steroid hormones
-derived from cholesterol -produced by gonads and adrenal cortex -Bind to intracellular receptors (in cytosol or nucleus) -function by binding to DNA to alter gene transcription -Slower and longer lived (have direct actions on DNA) -Not water soluble --> must be carried by proteins in bloodstream --> inactive while attached to carrier protein (must dissociate from carrier to function) -Have names that end in -one, -ol, or -oid (testosterone, cortisol, glucocorticoids)
Intermediate filaments
-diverse group of filamentous proteins -ex: keratin, destine, vimentin, and lamins -involved in cell-cell adhesion -help maintain integrity of the cytoskeleton overall -with stand tension -give cell structural rigidity -help anchor organelles (ex: nucleus) -they are specific to the type of cell and tissue
Male Sexual Development
-during the fetal period, the presence of the Y chromosome leads to the production of androgens --> results in male sexual differentiation -androgen production is low for childhood tho -then during puberty anterior pituitary releases FSH ad LH -FSH goes into blood stream and act on the sertoli cells of the testes, triggering sperm maturation -LH also acts on the interstitial cells of the testes and causes them to produce testosterone >Testosterone -develops and maintains the male reproductive system -results in development of secondary sexual characteristics such as: -facial and axillary hair -deepening of voice -increased muscle bone mass -testosterone levels remain high in adulthood but decline as men age -exerts negative feedback on the hypothalamus and anterior pituitary so its production is kept with in safe level
extraembryonic membranes
-embryo is connected to placenta by umbilical chord -before the placenta forms the embryo is supported by the yolk sac -yolk sac is the site of early blood cell development -The allantois is an extra embryonic membrane that is involved in fluid exchange between the embryo and the yolk sac -allantois is surrounded by the amnion which is a thin tough membrane filled with fluid. Serves as a shock absorber. **umbilical chord forms from remnants of the allantois and the yolk sac
How is a clot formed
-endothelium of blood vessel is damaged and collagen and a protein called tissue factor are exposed two things happen at same time: i) platelets come into contact with collagen and begin to aggregate and clump together on the exposed ECM. This activates the integrin αIIbβ3 on the platelet surface and causes it to attach to circulating proteins such as fibrinogen. ii)coagulation factors (which are secreted by liver) sense the tissue factor and initiate a cascade that ends with fibrin being formed --> At end of pathway prothrombin is made and it is converted to thrombin by thromboplastin -->thrombin then converts fibrinogen to fibrin which forms the small fibers that make cross links (netting) that catches RBCs and platelets to form a stable clot over damaged area
What stimulates production of RBCs
-erythropoietin is a hormone that is secreted by the kidneys -acts on bone marrow to cause production of RBCs
Telophase
-essentially the reverse of prophase -spindle apparatus disappears -nucelar membrane reforms -nucleoli reappear -chromosomes uncoil
Pregnancy
-fertilization has occurred and the zygote develops into a zygote that implants on the uterine lining and secretes human chorionic gonadotropin (hCG)--an analog of LH -hCG maintains the corpus luteum -hGC is critical during 1st trimester development bc it keeps the corpus luteum functioning which secretes the estrogen and progesterone that keep the uterine lining in place -then in the second trimester the placenta is large enough to secrete enough progesterone and estrogen by itself -so hGC levels decline -During pregnancy the high levels of progesterone and estrogen continue to serve as negative feedback to GnRH
Human gestation: second trimester
-fetus undergoes a tremendous amount of growth -begins to move in amniotic fluid -face takes on human appearance -fingers and toes elongate -and end its 30-36 cm long
Prophase
-first phase of mitosis -chromatin condenses in to chromosomes -centriole pairs separate and move to opposite poles of the cell -They are now in two distinct regions of the cell, these regions are called centrosomes -These centrosomes begin to make micro tubules that attach to the side of the cell and to chromosomes at the kinetochores (protein structures at the centromere of chromosomes) -also the nuclear membrane dissolves during prophase
Parathyroid gland
-four small pea sized glands on the posterior surface of the thyroid -hormone it produces is parathyroid hormone (PTH) -PTH acts opposite to calcitonin--it increases calcium levels: -it decreases the excretion of calcium by the kidneys -increases absorption of calcium in the gut (via vitD) -increases bone reabsorption --> high plasma calcium levels works as negative feedback on PTH -PTH also promotes phosphate reabsorption from bone and reduced reabsorption from the kidney -PTH activates Vit D which is required for calcium and phosphorous absorption in the gut -overall effect of PTH is an increase in calcium blood levels and little effect on phosphorous (bc absorption in gut and excretion in kidney cancels out)
Neornal activity is encoded by the _______ and ________ of action potentials
-frequency -number --> not dependent on the size of the action potential
why does brown fat help warm us better than white fat
-has an inefficient ETC which means much more heat energy is released as fuel is burned in them -->babies have lot of brown fat
villus structure
-has many microvillus on the cells (simple columnar) that make it up -also has a capillary bed to absorb water and nutrients -and a lacteal a lymphatic channel that takes up fats for transport into the lymphatic system
Atrial natriuretic peptide (ANP)
-heart endocrine function -released in response to stretching of the cells in atria -tells the heart that the blood volume is too high -result: promotes excretion of sodium and therefore water, increasing urine output -this lowers the blood volume and pressure -doesn't change blood osmolarity (bc both water and Na leave) **works in opposition to aldosterone
Diaphragm
-helps generate the negative pressure that allows the lungs to fill -thin muscular structure dividing the thoracic cavity from the abdominal cavity -under somatic control -other muscles from the back and neck and chest wall may also help out with breathing
Microtubules
-hollow polymers of tubular protein -radiate throughout the cell and are what the motor protein kinesis and dyne walk along -cillia and flagella are made of Mts -region of the cell called the centrosome contains certrioles which are what make the Mts -MTs attach to the kinetochore region of chromosomes to separate sister chromatids form each other during mitosis
Metaphase I
-homologous pairs align at the metaphase plate -each pair attaches to its spindle fiber by its kinetochore -each chromosome gets one micro tubule (online in mitosis where each got two on each side)
Granulocytes are involved in
-inflammatory reactions -allergies -pus formation -destruction of bacteria and parasites >types: Neutrophils, eosinophils, basophils
Why does diabetes cause polyuria and polydipsia?
-increased urination and thirst caused by: -You don't have any insulin (type I) or you are insensitive to it (type II) and that means you have high levels of glucose in the blood (hyperglycemia) -this overwhelms the nephrons filtering ability and you end up with glucose in the urine -The glucose is an osmotically active particle and takes water with it -this leads to higher urine output and excess urination (polyuria) -and because you are losing more water it leads to increased thirst (polydipsia)
prions
-infectious proteins -trigger misfiling of other proteins -usually convert protein in the alpha helical form to the beta pleated sheet form -this reduces the solubility of the protein -proteins eventually aggregate and interfere with cell function ex: mad-cow, cretzfeldt-jakob disease, and familial fatal insomnia
Endoderm
-innermost germ layer Produces: -epithelial linings of digestive and respiratory tracts -lungs -pancreas -thyroid -bladder -distal urinary tracts -parts of the liver ** Think endernal sounds like internal -->it lines all the internal organs and makes some of them up!
Type I Diabetes Mellitus
-insulin dependent - caused by autoimmune destruction of the beta cells of the pancreas leading to little or no production of insulin - require regular injections of insulin to permit entry of glucose into cells
smooth muscle characteristics
-lack striations -one nucleus -contains actin and myosin but is not as well organized as skeletal muscle -capable of more sustained contractions than skeletal muscle -can contract with out nervous system input -->has myogenic activity -contracts on its own in response to stretch and other stimuli
Bacterial growth curve
-lag phase: bacteria adapt to environment and do not really divide -log phase: rate of division increases exponentially -stationary phase: resources decrease and reproduction slows -death phase: bacteria have exceeded the ability for the environment to support them and they die
chromosomal mutations
-larger scale mutations where large segments of DNA are affected five types: i) deletion mutations ii) duplication mutations iii) inversion mutations iv) insertion mutations v) translocation mutations ** first three involve only a single mutation and last two involve two chromosomes
Leukocytes or WBCs usually comprise less than ___ percent of the total blood volume or _____ leukocytes per micro liter of blood
-less than 1% >4500-11,000 WBCs/uL of blood >If this percentage/number is higher that is a sign that body is fighting an infection
pineal gland
-located deep in the brain -secretes melatonin in response to decrease in light intensity -receives this message from the retina -involved in circadian rhythm
How would our respiratory system adjust if moved to higher altitudes
-lower oxygen would cause: short term: -breath more rapidly to avoid hypoxia -binding dynamics of hemoglobin shift due to 2,3-BPG (curve shifts right) -make more red blood cells long term: -develop more blood vessels to facilitate distribution of oxygen to tissues
lymphatic system; transportation of biomolecules
-lymph vessels also transport fats from the digestive system into the bloodstream -lacteals = small lymph vessels at center of each villus in the small intestine -fats are packages into chylomicrons by the mucousal cells and then enter the lacteal for transport >>Lymph vessels take the fats from the small intestine and deliver them to cardiovascular circulation **chyle = lymph fluid with lots of fats
Viral structure
-made of genetic material, a protein coat, and sometimes an envelope containing lipids -capsid --> protein coat -envelope--> made of phospholipids, surrounds capsid -lack ribosomes to carry out protein synthesis, why they must infect a host cell to >>they are: "obligate intracellular parasites" *sensitive to heat, detergents, and dessication *enveloped viruses are easier to kill
Flagella
-made of microtubules -structure involved in the movement of the cell itself -moves sperm cell thro reproductive tract -shares same 9+2 structure as cilia -9 MT doublets on the outside and 2 singlets in the inside -protein nexin keeps then attached and dynein sticks out of A tubule to walk along B tubule
Microfilaments
-made up of polymerized rods of actin -resist compression and fracture -can use ATP to allow for movement by interacting with myosin -responsible for muscle contraction -play a role in cytokinesis --> cleavage furrow is formed via MFs
Human gestation: first trimester
-major organs begin to develop during the first few weeks -heart begins to beat at 22 days -then eyes and liver and limbs and gonads form -by 5 weeks the embryo is 10mm in length -by week 6 its 15mm -at week 7 the cartilaginous skeleton begins to harden into bone -by week 8 most organs are formed and the brain is fairly developed and embryo is a fetus at end of three months the fetus is 9 cm long
oogenesis part 3 (zygote formation)
-mature ovum = large cell with lots of cytoplasm and organelles -it contributes almost everything to the zygote (1/2 DNA, all organelles, all cytoplasm, all RNA) -Sperm contributes 1/2 the DNA -after meiosis 2 is completed for the ovum, the sperm and ovum haploid nuclei join creating a diploid zygote
appendix proposed function
-may have role in warding off certain bacterial infections -thought to repopulate the large intestine with normal flora after episodes of diarrhea
Where are bacteria found in GI tract?
-mostly large intestine but also small intestine -mostly anaerobes -but cecum also home to some aerobic bacteria
Cilia
-motile structures composed of microtubules -project from a cell and help move materials along a cell surface -ex: they line the respiratory tract and help move mucus -have a 9+2 structure: -9 MT doublets on the outside and 2 singlets in the inside -protein nexin keeps then attached and dynein sticks out of A tubule to walk along B tubule
Prokaryotic cell structure
-no membrane bound organelles or nucleus and single celled -has a cell wall and a cell membrane (made of phospholipids -cell wall + cell membrane referred to as the cell envelope -bacteria always have at least one flagella (can have many tho) -Archaea also have flagella
Type II Diabetes Mellitus
-non-insulin dependent -caused by receptor level resistance to insulin - partially inherited and partially due to environmental factors like obesity and high sugar diet -meds can help body more effectively use the insulin it produces -these individuals only require insulin once their body can not regulate glucose levels even with help from medications
What causes an increased heart rate (NS and endocrine)
-norepinephrine from the sympathetic nervous system -epinephrine from the adrenal medulla -binds to adrenergic receptors in the heart and causes an increased heart rate and greater contractility
Prophase II
-nuclear envelope disappears -nucleoli disappear -centrioles migrate to opposite poles -spindle apparatus begins to form
Telophase II
-nuclear membrane forms -cytokinesis follows -4 haploid cells are produced per gametocyte
Features of a neuron
-nucleus is located in the cell body also called the soma -The cell has many appendages that emanate and are called dendrites which receive incoming information from other cells -The information received is transmitted thro the cell body before it reaches the axon hillock -The axon hillock plays an important role in action potentials - transmitting important info down the axon -Signals arriving will be either excitatory or inhibitory and the axon hillock sums up these signals -axon is a long appendage that terminates near a target structure such as a muscle or gland or another neuron -myelin prevents signal loss and increases the speed of conduction in the axon -myelin is produced by oligodendrocytes in the CNS and Schwann cells in the PNS -small breaks in myelin are called the nodes of Ranvier -at end of axon is the nerve terminal or the synaptic bouton (knob) --> releases NTs -nerons not physically connected to each other -->space btw is called the synaptic cleft
senescence
-occurs after 50 cell divisions -believe it is because of telomeres shortening -telomeres prevent loss of genetic info and prevent DNA from unraveling (have high G and C content, allowing them to overlap) >cells such as: germ cells, fetal cells, and tumor cells express the enzyme telomerase -telomerase has reverse transcriptase activity and so can synthesis the ends of the chromosomes and prevent senescence
menopause
-occurs because as a women ages her ovaries become less sensitive to FSH and LH -which results in ovarian atrophy -as estrogen and progesterone drop the endometrium atrophies and menstruation stops -now no negative feedback on FSH and LH so their levels rise -physical and physiological effects: flushing, hot flashes, bloating, headaches, irritability
What is reabsorbed and or secreted in the ascending loop of henle
-only permeable to salts and is impermeable to water -maximizes salt reabsorption due to decreasing osmolarity in the medulla -end of it = diluting segment
oogenesis part 2
-oocytes are surrounded by two layers: i)Zona pellucida -surronds the oocyte -mix of glycoproteins that protect and compounds needed for sperm cell binding ii) corona radiata -surrounds the Zona pellucida -is a cell layer that adheres during ovulation >meiosis II is triggered when a sperm cell penetrates these layers using acrosomal enzymes -now the secondary oocyte undergoes the secondary meiotic division to split into a mature ovum and polar body
Layers of the dermis
-papillary layer (upper layer next to epidermis) - reticular layer (bottom layer next to hypodermis)
Steps of G Protein-Coupled Receptors and hormone activation
-peptide hormone binds -causes alpha G protein to dissociate -goes and activates or inhibits adenylate cyclase enzyme -adenylate cyclase makes cAMP -cAMP binds to targets such as protein kinase A -protein kinase A phosphorylates transcription factor CREB -CREB goes into the nucleus and activates transcription of target genes
membrane lining lungs and thoracic cavity
-pleura -directly on top of lung = visceral pleura -on top of the visceral pleura and also lining the chest cavity = parietal pleura -space in btw = intrapleural space-has lubrication to let membranes slide past -the pressure differentials created across the plurals drive breathing
How does the hypothalamus regulate sexual reproduction?
-prior to puberty it restricts the production of gonadotropin-releasing hormone (GnRH) -At start of puberty hypothalamus begins releasing GnRH -This then triggers the anterior pituitary gland to synthesize and release follicle stimulating hormone (FSH) and luteinizing hormone (LH) -these hormones go on to trigger other sex hormones
Mitosis
-process by which two identical daughter cells are created from a single cell -consists of 4 stages: prophase, metaphase, anaphase, and telophase -occurs in somatic cells or cells that are not involved in sexual reproduction
Spermatogenesis process
-produce haploid sperm through meiosis -occurs in the seminiferous tubules >In males diploid cells are called spermatogonia -after replicating their genetic material (S phase) they are diploid primary spermatocytes -after the first meiotic division they are haploid secondary spermatocytes -These then undergo maturation to become spermatozoa *Therefore spermatogenesis results in four sperm for each spermatogonium
Complement system
-proteins in blood that act as nonspecific defense -can be activated thro classical pathway (antibody binds pathogen) or alternative pathway (no antibodies required) -complement proteins punch holes in the pathogen making its osmolarity off and cell unstable -even tho uses antibodies its nonspecific!!
G2 stage
-quality control checkpoint occurs -check for correct amount of organelles -checks to make sure DNA replication proceeded correctly
How is breathing regulated by the brain
-regulated by the ventilation center in the medulla oblongata -the neurons there fire to cause rhythmic contractions of respiratory muscles -neurons there contain chemoreceptors that are primarily sensitive to CO2 -When CO2 is high they cause an increase in the respiratory rate so that more CO2 is exhaled and its levels in the blood drop -they also sense O2 but not as much --> only really sense it and respond to it during hypoxemia -we can try to control our own breathing but if we under do it (hypoventilation) then the medulla oblongata kicks in jumpstarts breathing -also if we overdo it (hyperventilate) then get too low CO2 and the medulla oblongata also kicks in
What controls the gastric glands?
-respond to signals from the vagus nerve of the parasympathetic nervous system -the nerve is activated by the brain in response to the sight, taste and smell of food
enzymes that saliva contains
-salivary amylase (ptyalin) -> hydrolyzes starch into simpler sugars -lipase--> catalyzes hydrolysis of lipids
Glucagon
-secreted by alpha islet cells of the pancreas -increases blood sugar by triggering gluconeogenesis -increase glucose production -degrade fats and proteins >secretion is caused by: -low blood sugar -gastrointestinal hormones such as gastrin and cholecystokinin ->inhibited when blood glucose levels are high
insulin
-secreted by beta cells of pancreas -induces muscle and liver cells to take up glucose and store it as glycogen for later use -also stimulates fat and protein synthesis (bc glucose levels are high)
Oxytocin
-secreted by posterior pituitary at childbirth -allows for coordinated contraction of the uterine smooth muscle -also released when infant suckles at nipple --> causes contraction of the smooth muscle in the nipple to allow for milk ejection -also involved in bonding behavior **has a positive feedback loop: uterine contraction causes release of oxytocin which causes contraction which causes more oxytocin --> spirals forward until end result: delivery
The sensory neurons bring information in from the periphery and enter via the ______ side of the spinal chord. Motor neurons exit on the ____ side.
-sensory info enters on the dorsal side or the back side of the spinal chord. Their cell bodies are found in the dorsal root ganglia -Motor neurons leave on the ventral side or front side of the spinal chord. **remember this bc people with big muscles (motor neurons) are often pushy and will push their way to the front (ventral)
Endoplasmic reticulum
-series of interconnected membranes that are interconnected with the nucleus Rough ER (RER): -studded with ribosomes -this permits translation of proteins to be secreted into its lumen Smooth ER (SER): -lacks ribosomes -used mostly for lipid synthesis -and to detoxify certain drugs -also transports proteins from the RER to the golgi
Archaea
-single celled organisms -very similar to bacteria -but contain genes and metabolic pathways more similar to eukaryotes -they are known for their use of alternative energy sources -some are photosynthetic -some are chemosynthetic (can generate arg from inorganic compounds such as sulfur) Due to the similarities btw eukaryotes and Archaea its hypothesized they share a common origin -both start translation with methionine -both contain a similar RNA polymerase -both associate DNA with histones differences btw Archaea and eukaryotes: -archaea divide via binary fission -archaea contain singel circular chromosome -archaea share similar structure to bacteria but interestingly are resistant to many antibiotics *** Archea are in the prokaryotic category
Viroids
-small pathogens consisting of very short circular single-stranded RNA that infect plants -can bind to plant RNA and silence it -can also infect humans: ex: hepatitis D innocuous alone but with hep B it silences human hepatocytes (liver cells)
The diaphragm is under _____ control, while breathing itself is under _____ control
-somatic -autonomic
seminal fluid
-substance in which sperm are suspended -produced in combined effort by the seminal vesicles, the prostate gland, and the bulbourethral gland -seminal vesicles contribute fructose to nourish the sperm -seminal vesicles and the prostate gland contribute alkaline properties so sperm can deal with acidity of female reproductive tract -the bulbourethral glands produce clear viscous fluid that clears out the remnants of urine and lubricates the urethra during sexual arousal ** sperm + seminal fluid = semen
connective tissue
-supports the body and provides a frame work for epithelial cells -contribute to the stroma(support structure) of an organ -ex: bone, cartilage, tendons, ligaments, adipose tissue, and blood -most connective tissue secretes an extracellular matrix (materials like collagen and elastin)
Golgi apparatus
-system of stacked membrane bound sacs -materials from ER reach golgi via vesicles -cellular products are modified in the golgi thro the addition of carbs, phosphates and sulfates -golgi can also add signal sequences that direct profits where to go in the cell -if destined for secretion it leaves golgi and fuses with the plasma membrane and its contents are released via exocytosis
hypothalamus endocrine function
-the bridge between the nervous system and the endocrine system -regulates the pituitary gland with tropic hormones -controls the pituitary through both paracrine release of hormones into the portal system -helps control sleep-wake cycle from signals from light in retina (@ its suprachiasmatic nucleus) -regulates blood osmolarity -deals with apatite and satiety -regulated through negative feedback -->the hormone products that it causes to be released negatively regulate it
Reflex arcs (2 types)
-the neural circuits that control our reflex behavior -let us respond to stimuli at lower level of just spinal chord with out waiting for signal to be received by brain and analyzed -two types: i)monosynaptic: -there is a single synapse between the sensory neuron that received the singnal such as pain and the motor neuron that must respond to it. ex: knee jerk response ii)polysynaptic: -there is at least one interneuron between the motor neuron and the sensory neuron ex: withdrawl reflex -you step on nail and sensory neuron sends signal to motor neuron to with draw foot. But also you have to extend other foot to balance on --> this is communicated between the sensory neuron and an interneuron that connects to the motor neuron of the other foot/leg.
Adrenal cortex
-the outer portion of the adrenal glands -secretes corticosteroids: i) Glucocorticoids (glucose levels) ii) Mineralocorticoids (salt and water homeostasis) iii) Cortical sex hormones (androgens and estrogens)
oogenesis part I
-the production, growth, and maturation of an egg, or ovum -Females do not have an endless supply of stem cells analogous to spermatogonia; all the oogonia a women will have are formed during fetal development -by birth all the oogonia have already undergone DNA replication and are considered primary oocytes (2n) --[are arrested in prophase I] -When a women reaches menarche (1st menstrual cycle) one primary oocyte per month will complete meiosis I, producing a secondary oocyte and a polar body -polar body is produced because unequal cytokinesis occurs which gives almost all the cytoplasm to one daughter cell (the secondary oocyte) and nearly none to the other (polar body) -secondary oocyte remains arrested in metaphase II and doesn't complete it unless fertilized
Lung functions other than gas exchange
-thermoregulation -immune function (mucous traps) -control blood pH by controlling CO2 levels
diluting segment of loop of henle
-thicker bc the cells are larger bc have more mitochondria -this is to help them with the active transport of Na+ and Cl- begin reabsorbed from the filtrate -filtrate becomes hypotonic compared to tissue of kidney (only point ) -only portion of nephron that can produce urine thats more dilute than the blood -important bc provides mechanism so eliminate excess water if one is overhydrated
veins
-thin walled, inelastic vessels that transport blood to the heart
mnemonic for corticosteriods
-three S's Salt (mineralocorticoids) Sugar (glucocorticoids) Sex (cortical sex hormones) **all produced by?? -->adrenal cortex
The lymphatic system (anatomy)
-type of circulatory system -made up of one-way vessels that become larger as they move to the center of the body -the vessels carry lymph and join together to form large thoracic duct in posterior chest which then delivers the fluid into the left subclavian vein near the heart -lymph nodes = small bean shaped strutter that are along the lymphatic vessels. They contain a channel and an artery and a vein. They provide space for cells of immune system to meet pathogens
How are diuretics used in congestive heart failure to get rid of excess fluid?
-usually inhibit the reabsorption of Na+ from one portion of the nephron -means more Na+ stays in urine -bc Na+ is an osmotically active particle, more water stays in urine too -therefore more fluid is lost thro urine
High frequency recombination bacteria
-usually only the plasmid is transferred across the bridge during conjugation -but sometimes the plasmid itself can get integrated into the bacterias genome, like when it is picked up via transformation -in this case when a bacteria with the sex factor in its genome forms a bridge to carry out conjugation, the whole genome is attempted to be transferred bc the plasmid is within the genome!! -however the bridge usually breaks before the whole DNA sequence is moved into new bacteria -cells that have the sex factor in their genome are called high frequency recombination cells or Her cells.
Ways CO2 is carried through the blood
-very small amount dissolves in blood -small portion enters RBCs and attaches to hemoglobin (but has much lower affinity than O2) -majority is converted into carbonic acid by carbonic anhydrase (an enzyme in the RBC) -carbonic acid then dissociates into a proton and the bicarbonate ion -In the lungs the H+ and HCO3- recombine into carbonic acid which is then converted back into CO2 and H2O by carbonic anhydrase so CO2 can be expelled
capillaries
-vessels with a single endothelial cell layer -they allow for easy diffusion of gases and nutrients and wastes and hormones -->when damaged blood goes into the interstitial space
Immune function of the respiratory system
-vibrissae, mucous membranes, and the mucociliary escalator help filter the incoming air and trap particulate matter -lysozymes in the nasal cavity and saliva attack peptidoglycan cell walls of gram-positive bacteria -mucociliary escalator: cilia propel mucus up the respiratory tract to the oral cavity, where it can be expelled or swallowed -macrophages can engulf and digest pathogens and signal to the rest of the immune system that there is an invader -mucosal surfaces are covered with IgA antibodies -mast cells have antibodies on their surface that, when triggered, can promote the release of inflammatory chemicals (often involved in allergic reactions)
Viral Life Cycle: Infection
-virus can only infect cells that have certain receptors on their surface that the virus can bind to -enveloped viruses bind to the plasma membrane of a cell and inject virion into cell -bacteriophages only insert genetic material into cell -HIV(retrovirus) enters cell intact
Example of the steps in an immune response to an intracellular pathogen
-virus infects a cell -the infected cell secretes interferons -the interferons make the neighboring cells less permeable and reduces their rate of transcription/translation and causes flu symptoms -The infected cells also present antigens of the virus on their surface with MHCI -CD8+ T-cells recognize the viral antigens as non self and inject toxins into the cell to promote apoptosis -If the virus down regulates the production of MHC-I then natural killer cells will recognize this and cause apoptosis in the cell **memory T-cells will be made so next time virus invades, faster response
How does the endocrine system cause lactation from a mother
-when don't need to produce milk the hypothalamus surpasses the anterior pituitary from releasing prolactin by secreting PIF (dopamine) -then the mother is pregnant and the high levels of estrogen and progesterone cause her to develop milk ducts -after expulsion of placenta estrogen and progesterone and dopamine levels all drop. -then when baby latches onto nipple oxytocin is released from the posterior pituitary and then smooth muscle of the breast contracts resulting in the ejection of milk thro the nipple -then hypothalamus stops inhibiting prolactin(again?) and then prolactin is released and milk production occurs
codominance (genetics)
-when more than one dominant allele exists for a given gene ex: The A and B alleles for blood type -person will have AB blood type bc they are codominant
White matter and gray matter in the spinal chord
-white matter lies on the outside of the chord and grey matter is deep within it
What triggers bone to be broken down
-you have low calcium levels and the body senses it -releases parathyroid hormone from the parathyroid glands -this causes the body to reabsorb bone and increases calcium and phosphate levels in the blood -PTH also activates vitamin D which increases reabsorbtion of bone so that stronger bone can be bulit in its place
One centiMorgan (cM) is one map unit and corresponds to _____ percent chance of recombination occurring btw two genes
1 %
Each red blood cell can carry how much oxygen
1 billion molecules bc has 250 mill heme and each can carry 4 O2 molecules
Each kidney contains about _____ nephrons
1 million
neurulation steps
1) A rod of mesodermal cells known as the notochord forms along the long axis of the organism like a primitive spine 2) These notochord cells induce the overlying ectoderm cells to slide inward and form neural folds and a neural grove 3) The neural folds grow towards each other till they form a neural tube which gives rise to the central nervous system 4) At the tip of the neural tubes are neural crest cells which migrate outward and make up the peripheral nervous system (PNS). 5)Ectodermal cells migrate over the neural tube to cover the rudimentary nervous system
path of air to lungs
1) external nares 2)nasal cavity w/ vibrissae 3)pharynx 4) Larynx 5) trachea 6) bronchi 7) bronchioles 8) alveoli
Steps in inhalation
1) Diaphragm and external intercostals expand the chest cavity 2) This volume expansion leads to a decrease in the intrapleural pressure (boyle's law) 3) This means the pressure in the lungs is greater than that in the intrapleural space. This causes the lungs to expand into the intrapleural space 4) This increase in volume in the lungs makes the pressure in the lungs drop 5) This causes air to be sucked from high-pressure environment (outside) into the low pressure of the lungs **Called negative pressure breathing
Differences between eukaryotes and prokaryotes
1) Eukaryotes can have multiple cells while prokaryotes are single celled 2) Eukaryotes contain a true nucleus enclosed in a membrane, prokaryotes do not 3)prokaryotes do not contain membrane bound organelles, eukaryotes do 4) prokaryotes contain a single circular molecule of DNA
Three main functions of endothelial cells in blood vessels
1) Help maintain the vessel by releasing chemicals that aid in vasoconstriction and vasodilation 2) Allow leukocytes to pass thro the vessel wall and enter the tissue to help fight infection 3) When damaged they release chemicals that aid in formation of blood clots to help repair the vessel
How do veins push blood up against the force of gravity?
1) Larger veins contain valves that prevent back flow Failure: varicose veins 2) Most veins are surrounded my skeletal muscles that help to push blood up to the heart Failure (if siting still too long): clots in legs
What are the three ways in which a neurotransmitter is removed from the synaptic cleft?
1) NT can be broken down via an enzymatic reaction. -->example of this is acetylcholine (ACh) 2) NT can be brought back into the presynaptic neuron using reuptake carriers -->ex: serotonin, dopamine, and norepinephrine 3) NT can diffuse out of the synaptic cleft like with nitric oxide (NO).
Antibodies three jobs /things they cause to occur
1) Opsonization: Antibodies bind to a specific antigen and attract other leukocytes to phagocytize the antigens immediately 2)Agglutination: Antibodies cause pathogens to clump together which forms large and insoluble masses that are easy to phagocytize 3) Neutrilization: Antibodies block the ability of pathogens to enter tissues which neutralizes them
What are the conditions for Hardy-Weinburg equilibrium?
1) Population is very large (no genetic drift) 2) There are no mutations that affect the gene pool 3) Mating btw individuals in a population is random (no sexual selection) 4) There is no migration between individuals into or out of the population (no gene flow) 5) The genes in the population are all equally successful a being reproduced (no natural selection) -->so evolution is not occurring
The noncellular innate immune system
1) Skin: -physical barrier -has antibacterial enzymes ->defensins -sweat has antimicrobial properties -1st line of defense! 2)Mucous membranes of the respiratory system -traps matter -cilia pushes it up to be swallowed or expelled 3) other mucous membranes -around the eye and oral cavity -produce enzyme > lysozyme (nonspecific bacterial enzyme) 4) The gastrointestinal tract: -stomach acid kills pathogens -bacterial population in gut outcompetes invaders for food 5)Complement system -proteins in blood that act as nonspecific defense -can be activated thro classical pathway (antibody binds pathogen) or alternative pathway (no antibodies required) -complement proteins punch holes in the pathogen making its osmolarity off and cell unstable -even tho uses antibodies its nonspecific!! 6)Interferons -cells that are infected with a virus produce these proteins that prevent viral replication -makes the nearby cells decrease production of proteins -also decreases permeability of close cells -up regulate MHC class I and II proteins so the cells nearby have increased antigen presentation -cause flu-like symptoms such as tiredness and muscle soreness and fever
Three portal systems in the body
1) The hypophyseal portal system (connects hypothalamus and anterior pituitary) 2) The hepatic portal system (connects the gut tube and the liver) 3) The renal portal system (glomulerus and vasa recta)
What cell type/s make up the gastric gland?
1) mucous cells 2) chief cells 3) parietal cells
steps taken in body to release urine
1) stretch receptors in bladder tell brain that its full 2) parasympathetic activity detrusor muscle (lines the bladder) to contract 3) This causes the internal sphincter to relax (micturition reflex) 4) Then the person can chose to relax their external sphincter to urinate or keep it contracted and wait to pee -->also abdominal muscles contract and compress the bladder to help with urination
RBCs are biconcave which is good for what two reasons?
1)Assists them with traveling through tiny capillaries 2) It increases the cell's surface area which increases gas exchange
What are the 6 key products that the stomach secretes
1)HCl- kills microbes, denatures proteins, converts pepsinogen to pepsin 2)Pepsinogen- cleaved in the stomach to pepsin; enzyme that partially digests proteins 3) Mucus - protects mucosa 4) Bicarbonate 5) Water - dissolves and dilutes ingested material 6) Intrinsic factor - required to absorb B12
All blood cells can be divided into three lineages
1)RBCs or erythrocytes -->derived from myeloid stem cell 2)Lymphocytes: -all derived from common lymphoid progenitor -composed of B-cells, T-cells, and natural killer cells 3) Myeloid lineage: -derived from common myeloid progenitors -composed of granulocytes, megakaryocytes and macrophages -roles in innate immunity and blood clotting
Cell specialization steps
1)Specification -cell is reversibly designated to a specific cell type 2)Determination -the commitment of a cell to a particular function in the future 3)Differentiation -The cell undergoes changes in structure, function and biochemistry that cause the cell to develop into the determined cell
What are the three fetal shunts?
1)foramen ovale -one way vale from the right atrium to the left atrium -this allows the blood to skip over the pulmonary circulation and go right to the systemic circulation -the blood here has already been oxygenated by the mother so doesnt need to go to the lungs -in fetuses the pressure in the right atrium is higher -when they are born the pressure switches causing this opening to close 2)ductus arteriosus -shunts left over blood from the pulmonary artery to the aorta -to send blood right to systemic circulation -also pressure is higher on right side which allows this to occur 3)1)ductus venosus -shunts blood that is returning from the placenta via the umbilical vein directly into the inferior vena cava -this avoids sending the blood to the fetus's liver which is not functioning yet and also the blood has already been detoxified bc its from mom!
Three types of neurons
1)sensory neurons -also called affront neurons -transmit sensory info from the sensory receptors to the spinal chord and brain 2)motor neurons -also called efferent neurons -transmit motor info from the brain and spinal chord to muscles and glands 3)interneurons -found between the other neurons
Cardiac muscle cells have how many nuclei?
1-2
three parts of the pharynx
1. Nasopharynx (behind the nasal cavity) 2. Oropharynx (at back of mouth) 3. Laryngopharynx (above the vocal chords)
The actin-myosin cross bridge cycle
1. resting stage, ATP is hydrolyzed 2. Ca²⁺ binds to troponin, myosin binds to actin 3. powerstroke occurs, the sarcomere contracts, ADP and Pi dissociate from myosin 4. new ATP binds to myosin, causing detachment of myosin from actin; hydrolysis of ATP to ADP and Pi causes recocking of the myosin head -key point: it is the dissociation of ADP and Pi from myosin that is responsible for the powerstroke, NOT the hydrolysis of ATP
surface area of gas exchange due to branching of alveoli
100 m^2 total
The kidneys filter ___liters of blood per day
180 -->36 times our blood volume
Crossing two heterozygotes for a trait with complete dominance results in what ratio for genotypes? wha ration for phenotypes?
1:2:1 ratio for genotypes 3:1 ratio for phenotypes
what percent of blood that passes through the glomerulus is filtered into Bowman's space
20%
Biological sex is determined by the ______ pair of chromosomes
23rd
blood osmolarity is usually maintained at
290 miliosmoles (mOsm)
average cardiac output for humans
5 L per min
Blood composition
55% liquid, 45% cells Plasma = liquid portion of blood -->mix of nutrients, salts, respiratory gases, hormones and blood proteins cells= erythrocytes, leukocytes, and platelets
The SA node has an intrinsic rhythm of ____ signals per minute
60-100 -If an athlete can be as low as 40-50 -If scared can be above 100
The body attempts to maintain a pH between?
7.35 and 7.45 ->below = academia ->above = alkalemia
Normal partial pressure of O2 in arterial blood?
70-100 mmHg
enzymes in the duodenum work best at what pH?
8.5
healthy people have an oxygen saturation about
97%
Cross individuals and follow two traits that are both heterozygous (dihybrid cross), what are the phenotypic ratio of the offspring
9:3:3:1 9=dominant dominant 3=recessive dominant 3=dominant recessive 1=recessive recessive
Three major T-cells
>Cytotoxic T cells: CD8+ T-cells, respond to MHC I >Helper T cells: CD4+ T-cells, recruit other immune cells thro secreting lymphokines >Suppressor T cells: express CD4+ and Foxp3, tone down immune response, and turn off self reacting lymphocytes ***memory T-cells are a fourth less common type. These can be generated and lie in wait till the antigen is seen again
maternal health affects development
>diabetic women with hyperglycemia can have poor birth outcomes -can leave to a fetus that is too large -and one that has hypoglycemic bc has synthesized very high levels of insulin to compensate for mother's high blood glucose level >Maternal folic acid deficiency -can prevent complete closure of the neural tube -leading to spina bifida (parts of nervous system are exposed to the outside world) -or to anencephaly (brain fails to develop)
Law of segregation (medals first law) -What are the 4 tenets?
>genes exist in alternative forms >An organism has two alleles for each gene -- one inherited from each parent >The two alleles segregate during meiosis, resulting in gametes that carry only one allele for any inherited trait >If two alleles of an organism are different, only one will be fully expressed and the other will be silent (codominance and incomplete dominance are exceptions)
indeterminate cleavage vs.determinant cleavage
>indeterminate cleavage -results in cells that can still develop into complete organisms -cells fates are not decided yet -monozygotic twins arise this way when embryos go thro indeterminate cleavage >Determinant cleavage -results in cells with fates that are already determined -cells are committed to differentiating into certain type of cells
If a patient has decreased surface area in the alveoli and decreased recoil. This will result in: a)increased residual volume b)decreased total lung capacity c) increased blood oxygen level
A -The intrinsic elastic properties of the lung are important during exhalation as the passive recoil of the lung tissue helps decrease lung volume -Therefore with decreased recoil the patient won't be able to exhale as much, increasing the residual volume (or air left in lungs after exhalation) -the decreased surface area would result in lower O2 levels
missense mutation
A base-pair substitution that results in a codon that codes for a different amino acid. -->results in one different amino acid in the final protein
genetic drift
A change in the gene pool of a population due to chance -more pronounced in small populations -extreme examples of genetic drift: i)The founder effect ii)Bottlenecks
monohybrid cross
A cross between individuals in which only one trait is being studied P generation = individuals being crossed F generation = offspring
dihybrid cross
A cross between two individuals, concentrating on the inheritance two different genes -->Punnett square is 4x4 or 16 boxes total
binary fission
A form of asexual reproduction in single-celled organisms by which one cell divides into two cells of the same size -the circular chromosome attaches to the cell wall and replicates while the cell grows in size -eventually the cell wall and PM grow inward -much more rapid than mitosis -20 min in e.coli
species
A group of similar organisms that can breed and produce fertile offspring.
erythropoietin
A hormone produced and released by the kidney that stimulates the production of red blood cells by the bone marrow. -released in response to low blood oxygen levels
Cholecystokinin (CCK)
A hormone secreted by the small intestine (duodenum) in response to the presence of fats and amino acids -->It promotes release of bile from the gallbladder and pancreatic juice from the pancreas. ---> also acts on the brain to promote satiety
motor unit
A motor neuron and all of the muscle fibers (or myocytes) it innervates
anus
A muscular opening at the end of the rectum through which waste material is eliminated from the body
esophagus
A muscular tube that connects the mouth to the stomach. Top third = skeletal muscle middle third = mix of skeletal and smooth muscle bottom third = smooth muscle ---> top third controlled by the somatic (voluntary) nervous system -->bottom two thirds controlled by autonomic (involuntary)
silent mutation
A mutation that changes a single nucleotide, but does not change the final protein created -->usually when the third NT in a codon bc there is degeneracy (wobble) to the genetic code
The cytoskeleton
A network of fibers that holds the cell together, helps the cell to keep its shape, and aids in movement Three components: -microfilaments -microtubules -intermediate filaments
gastrin
A peptide hormone that induces the parietal cells in the stomach to secrete more HCl and signals the stomach to contract, mixing its contents -->secreted by G-cells
hepatic portal vein
A vein connecting the capillary bed of the intestines with the capillary bed of the liver. This allows amino nutrients absorbed from the intestines to be delivered first to the liver for processing before being transported throughout the circulatory system.
Bacteriophage
A virus that infects bacteria -don't enter bacteria, just inject genetic material -have a capsid but no envelope -have tail sheath: acts like a syringe to inject genetic material -have tail fibers: help bacteriophage recognize and connect to the host cell
posterior pituitary hormone products
ADH and Oxytocin -caused by neuron stimulation from hypothalamus **both of these are made in the hypothalamus too and stored in posterior pituitary -->therefore the posterior pituitary doesn't actually make any hormones itself
What hormones trigger sensation of thirst
ADH and aldosterone
active immunity vs passive immunity
Active immunity: The immune system is stimulated to produce antibodies against a certain pathogen -->natural: you encounter pathogen in daily life -->artificial: A vaccine is administered and you are given a weakened or dead version of the pathogen to make antibodies against >>>Takes longer to acquire by long lived Passive immunity: Antibodies are transferred to the individual. -This occurs in the womb, mother gives antibodies to baby -Also can be administered via injection if you have rabbies >>>Can acquire it immediately but is short lived
Why does rigor mortis occur?
After death you don't make any ATP -->this means myosin heads can not detach from actin (bc that's the job of ATP binding) -->so the muscles can't relax and lengthen
pancreatic juice
Alkaline mixture of water, enzymes, zymogens, sodium bicarbonate and other electrolytes >The bicarbonate helps neutralize the acidic chyme and creates an ideal working environment for the digestive enzymes (pH 8.5) >pancreatic juices contain enzymes that can break down all three types of nutrients (fats proteins carbs)
Residual Volume (RV)
Amount of air remaining in the lungs after a forced exhalation -around 2 liters
expiratory reserve volume(ERV)
Amount of air that can be forcefully exhaled after a normal tidal volume exhalation
Inspiratory Reserve Volume (IRV)
Amount of air that can be forcefully inhaled after a normal tidal volume inhalation
Lysosomes
An organelle containing hydrolytic enzymes -often function in conjunction with endosomes -endosomes transport materials from the trans-golgi to the cell membrane but also bring material to be degraded in lysosomes -The lysosome sequesters the enzymes so cell isn't damaged -but if these enzymes are released it results in apoptosis via autolysis
How do RBCs produce ATP?
Anaerobic respiration --> glycolysis -so generate lots of lactate through fermentation
A child is born with an imperforate anus, in which an anal canal fails to form correctly. This is likely caused by failure of?
Apoptosis -->Apoptosis helps form the lumen in the digestive tract -if it doesn't occur you could get an imperforate anus
blood leaving the heart path through vessels
Arteries--> arterioles --> capillaries --> venules -->veins
Clevage of the zygote
As it moves to the uterus for implantation, the zygote undergoes rapid mitotic divisions in a process called cleavage -The first cleavage officially creates an embryo! -During the first few rounds of cell divisions the size of the embryo stays the same and the cell size just gets smaller -this increases N:C (nucleus to cytoplasm) ratio -and it increases the surface area to volume ratio -->this increases cell's gas exchange and nutrient exchange
The menstrual cycle: the menstruation phase
Assuming implantation does not occur: -corpus luteum loses stimulation from LH -progesterone levels decline -uterine lining falls off -estrogen falls -now with low levels of estrogen and progesterone, GnRH can be produced again so next cycle can occur
Which two types of glial cells, if not properly functioning, will make an individual most susceptible to a CNS infection?
Astrocyte and microglia
Net pressure at the arteriole and venule end of a capillary bed
Ateriole = 11 mmHg out (36 out - 25 in) venule = 10 mmHg in (15 out - 25 in)
Valves of the heart
Atrioventricular: Tricuspid= btw RA abd RV Mitral(bicuspid)= btw LA and LV LAB RAT Semilunar: Pulmonary= btw RV and pulmonary artery Aortic= btw LV and aorta
which of the following would NOT be expected in an individual taking medications with anticholinergic activity? a)Dry mouth b)Diarrhea c) slow gastric emptying d) decreased gastric acid production
B -->parasympathetic nervous system is blocked partially -->secretion from glands occurs (A and D) --> blocks parastalsis so slow gastric emptying occurs -and this in turn would allow more water to be absorbed which would result in constipation not diarrhea (B)
Which of the following statements regarding the periosteum is false? a) it serves as a site of attachment of bone to muscle b) it secretes fluid into the joint cavity c) it is a fibrous sheath that surrounds long bones d) is may differentiate into osteoblasts
B some peristeum cells are capable of differentiating into bone-forming cells or osteoblasts --> why D is correct B is wrong bc thats the job of the synovium
What feature of the veins allows for more blood to be held in them at any given time than in the arterial system? a) Presence of valves b) lack of smooth muscle in the wall c) Thin endothelial lining
B --> both arteries and veins are only one endothelial cell thick --> but arteries have thicker walls due to the smooth muscles surrounding them
In which segment of the nephron is sodium NOT actively transported out? a) PCT b) Thin part of the ascending loop of henle c) thick part of the ascending loop of henle d) DCT
B thin part of the ascending loop is in the inner medullary and the ion of sodium diffuse passively out
anaerobe bacteria (types)
Bacteria that doesn't need oxygen types: -obligate anaerobe: bacteria that can't survive in an oxygen containing environment (bc causes them to produce ROS) -facultative anaerobe: bacteria use oxygen if its present but switch to not using it if it isn't -aerotolerant anaerobe: bacteria that don't use oxygen but are not harmed by its presence
lymphatic system; equalization of fluid distribution
Because the pressure that pushes fluid out at the arterial end is slightly less than the pressure that sucks the fluid back up at the venule end, a small amount of fluid remains in the tissues -Lymphatic vessels drain these tissues and return the fluid to the blood stream -If you have a low amount of protein in the blood there is a low oncontic pressure and then less fluid will be driven back into the blood. Lymph vessels take care of the extra fluid --> but if lymph vessels are overwhelmed then edema can occur
When a muscle contracts and a sarcomere changes shape, how fo all the different bands and zones change or not change in size?
Becomes smaller: -H-zone -I-band -the distance btw Z-lines -the distance between M-lines Stays the same: -A-band's size
normal blood pressure
Between 90/60 and 120/80 systolic (contraction)/ diastolic (relaxation)
Which blood type is the universal acceptor?
Blood type AB (positive- has Rf factor) -->This person has both A and B anitgens on the surface of their RBCs >this means that they will bc able to recognize types A and B as self and type O has no antigens so will not trigger an immune response
osteoclasts
Bone-destroying cells -->the resident macrophages of bone
Positive and negative selection of T-cells
Both occur in the thymus Positive: Only allows the cells that respond to antigen on MHC to survive Negative: Causes apoptosis in cells that are self reactive (they have been activated by a self protein)
List the structures of the excretory pathway, from where filtrate enters the body to where urine leaves
Bowman's space --> PCT ->descending LOH--> Ascending LOH -> DCT ->collecting duct -> renal pelvis -> ureter -> bladder ->urethra
Enzymes secreted by the small intestine
Brush-border enzymes: ex: Disaccharidases (maltase, sucrase) peptidases (dipeptidase) --> break down dimers and trimers into absorbable monomers
cardiac output equation
CO = HR x SV (heart rate x stroke volume) HR = beats/min SV = volume of blood pumped/beat CO= the total blood volume pumped by a ventricle in a minute
Macrophage called __?____ in the CNS, skin and Bone
CNS--> microglia Skin --> Langerhans cells Bone --> osteoclast
If you hyperventilate, how will the bicarbonate buffer system compensate?
CO2 (g)+ H2O(l)↔H2 CO3 (aq)↔H+ (aq)+HCO3- (aq) -->If CO2 is exhaled at increased levels then the reaction will shift left, decreasing the H+ in the blood and raising the pH -->the result will be respiratory alkalosis --> the kidney will compensate for this change by increasing excretion of bicarbonate which will shift the reaction right and level out the pH
How does body deal with renal tubular acidosis type I (kidney can't excrete acid effectively)
CO2 (g)+ H2O(l)↔H2 CO3 (aq)↔H+ (aq)+HCO3- (aq) -leads to a build up of H+ in the blood -This shifts the reaction left so get excess CO2 -Body compensates by increasing exhalation of CO2 (hyperventilation) -This loss of CO2 shifts the reaction left and lowers the H+ being produced, brining the pH back to normal
Bicarbonate buffer system
CO2 (g)+ H2O(l)↔H2 CO3 (aq)↔H+ (aq)+HCO3- (aq) mechanism that deals w/ acidemia (excess H+ in blood), causes the reaction to shift left so more CO2 in blood. Then: -Blowing off CO2 (hyperventilation) decreases levels of CO2 which causes reaction to shift left consuming H+ and reducing H+ in the blood making pH less acidic
Steps after Ca2+ is released from sarcoplasmic reticulum until myosin binds
Ca2+ is released by depolarization brought on by action potential -Calcium ions bind to a regulatory subunit in troponin -this triggers a change in the confirmation of tropomyosin -this change exposes the myosin binding sites on the actin filaments
What does mutation of the TP53 gene cause?
Cancer -this is the gene that produces p53, the protein that controls the G1/S and G2/M checkpoints leading up to mitosis -When this gene is mutated the cell is not stoped to repair damaged DNA before dividing -This results in accumulation of mutation, eventually leading to a cancerous cell that divides continuously without regard for quality or quantity of new cells produced -leads to tumors -then eventually metastasis
Summary of how nutrients, wastes and hormones enter the circulatory system
Carbs + AAs --> absorbed into capillaries of small intestine ---> hepatic portal system --> systemic circulation Fats--> lacteals in small intestine --> packaged into water soluble lipoproteins --> thoracic duct --> systemic circulation CO2, urea, NH4+ in tissues ---> travel down conc. gradient --> blood stream --> kidneys Hormones ---> exocytosis from cells of tissue produced in ---> blood --> cell surface receptor (peptide hormone) or intracellular receptor (steroid hormone)
What measurement is the same between the two ventricles?
Cardiac Output (CO) CO= the total blood volume pumped by a ventricle in a minute
matrix of cartilage? what cells secrete this?
Cartilage matrix = chondrin secreted by chondrocytes
What does the disassociation of ADP and Pi from the myosin head cause
Causes the power stroke
neural crest cells
Cells at the tip of the neural fold; this group of cells gives rise to many components of the peripheral nervous system. Examples: >PNS cells -sensory ganglia -autonomic ganglia -adrenal medulla -Schwann cells >cells of other tissues: -calcitonin producing cells of the thyroid -melanocytes of the skin
What hormones trigger feelings of satiety?
Cholecystokinin (CCK) and Leptin
What are the differences between compact and spongy bone?
Compact: -denser and used for its strength -forms the outer layers of bone Spongy (cancellous): -has many spaces btw boney spicules (trabeculae) -is the site of marrow production -found in the interior core of bone -helps to distribute forces or pressures on the bone
lamellae
Concentric circles of bony matrix within the Haversian systems of bone.
erthyroblastosis fetalis
Condition in which the mother of the baby is Rh- and she has had a child that is Rh+ so she develops anti-Rh+ antibodies --> This occurs only once she has had a second child that is Rh+ becuase now her immune system is armed against it -->The anti-Rh+ antibodies cross the placenta and resulting in hemolysis of the fetal cells **Only a concern with Rh and not ABO mismatch bc Rh antibodies are IgG and so can cross placenta whereas ABO antibodies are IgM and so can not
Bile ducts
Connect the liver with both the gallbladder and small intestine --->Bile is produced in the liver and can be stored in the small intestine or secreted into the duodenum
tonus
Constant state of low-level contraction -seen in smooth muscle like blood vessels -not seen in skeletal muscle
What can increase the likelihood of a deep vein thrombosis
DVT is a type of clot that forms in the deep veins of the leg --> increase chance of getting this if you sit still for long periods of time --> If clot dislodges can travel up and through the heart an into the lungs and cause a pulmonary embolus
Depolarization of the neuron is caused by ____. Whereas hyperpolarization is caused by_________. What does each result in for the membrane potential?
Depolarization is caused by excitatory input and leads to raising the membrane potential from its resting potential. Hyperpolarization is caused by inhibitory input and results in lowering the membrane potential.
muscles used in inhalation
Diaphragm, External intercostal muscles, Accessory muscles assist in elevating ribs -->results in expansion of thoracic cavity
Long bone structure: Diaphysis, metaphases, and epipyses
Diaphysis = cylindrical shafts Meaphyses = where it swells at each end epiphyses = where it tapers off at each end (full of spongy bone)
Meiosis vs. mitosis similarities and differences
Differences: -occurs in gametocytes (germ cells) -results in 4 nonidentical sex cells (gametes) -meiosis consists of one round of replication followed by two rounds of division -Meiosis I results in homologous chromosomes being separated generating haploid daughter cells (reductional division). -Meiosis II is similar to mitosis bc results in the separation of sister chromatids with out a change in ploidy (equational division) Similar: -genetic material is duplicated -chromatin is condensed to form chromosomes -Microtubules help divide genetic material -meosis II is similar to mitosis
Cytokinesis
Division of the cytoplasm and organelles during cell division -occurs at end of telophase **remember each cell can only undergo a finite number of cell divisions before cell death. For human somatic cells that is about 20-50 divisions
Major waste products excreted in the urine
Dump the HUNK H+ Urea NH3 K+
small intestine anatomy
Duodenum - most chemical digestion Jejunum - prominent site for nutrient absorption Ileum - more absorption (B12 and bile salts) D->J->I (up to 7m long)
Endocrine vs exocrine function of pancreas
Endocrine: secretes insulin, glucagon and somatostatin (cells= islets of langerhans) Exocrine: secretes pancreatic juices (cells= acinar cells)
Where do cylomicrons go after formed
Enter lymphatic circulation thro lacteal in the villus. -->lacteals converge and enter the venous circulation at the thoracic duct in the base of the neck, which empties into the let subclavian vein
Avery experiment
Experiment that discovered DNA, not protein, to be the agent responsible for transformation -->saw that when treated with proteases the bacteria was transformed and mice died -->when treated with DNAses the bacteria was not transformed and the mice lived
Mnemonic to help remember the anterior pituitary products
FLAT PEG FSH LH ACTH TSH Prolactin Endorphins Growth hormone (GH) FLAT are all tropic hormones and PEG are all direct hormones
directional selection
Form of natural selection in which the entire curve moves; occurs when individuals at one end of a distribution curve have higher fitness than individuals in the middle or at the other end of the curve ex: emergence of bacteria that are resistant to an antibiotic
What cell type/s make up the pyloric glands?
G-cells (that secrete gastrin)
What are the four phases in the cell cycle?
G1, S, G2, M -G1, S, G2, are all part of interphase -interphase is the longest part of the cell cycle (90% of cells time spent here) -During interphase chromosomes are less condensed as chromatin -cells not dividing spend all there time in an offshoot of G1 called G0. -During G0 the cell is living and carrying out fun without preparing for division
advantageous mutation
Genetic changes that improve their carriers' chances of producing fitter offspring ex: heterozygous for sickle cell trait gives you resistance to malaria
What is one drug to give to treat autoimmune diseases?
Glutocorticoids -has potent immunosuppressive qualities
all of the different hormones that hypothalamus secretes and the response hormones from the anterior pituitary
Gonadotropin-releasing hormone (GnRH) --> Follicle stimulating hormone (FSH) and luteinizing hormone (LH) Growth-hormone releasing hormone (GHRH) --> growth hormone (GH) Thyroid releasing hormone (TRH) --> thyroid stimulating hormone (TSH) Corticotropin releasing factor (CRF) --> adrenocorticotropic hormone (ACTH) *prolactin inhibiting factor (PIF) --X-->X prolactin secretion last one is the odd one bc it causes the anterior pituitary to stop releasing something instead of activating it to release something
granulocytes vs agranulocytes
Granulocytes- have specific granules - last only a few days -types: Neutrophils, eosinophils, basophils Agranulocytes- Lack specific granules -live several months/year - types: lymphocytes and monocytes
When the pH of the blood is high, what substance is likely to be seen in large quantities in the urine?
H+
Aldosterone increases the excretion of
H+ and K+ ions
parietal cells secrete
HCl and intrinsic factor HCI: -breaks pepsin to pepsinogen -kills microbes -denatures proteins -breaks down some intramolecular bonds intrinsic factor: -glycoprotein that helps absorb B12
Equation for heart rate
HR = CO/SV CO = cardiac output SV = stroke volume
Canaliculi
Hairlike canals that connect lacunae to each other and the central canals --> allow for exchange of waste between the osteocytes and the Haversian and volkmann's canals
What is ADH secreted in response to?
High blood osmolarity --> triggers the posterior pituitary to secrete ADH
Anaphase 1
Homologous chromosomes separate -process is called disjunction (accounts for medals first law) -During disjunction the two chromosomes that were attached now separate and each one can go to either daughter cell (maternal and paternal chromosomes can go to either side) -so distribution of the chromosomes does not depend on which parent they came from ... completely random
pancreatic lipase
Hydrolyzes ester bond of lipids (breaks down fats into free fatty acids and glycerol) (secreted as part of pancreatic juice into duodenum)
(pro)carboxy peptidases A and B
Hydrolyzes terminal peptide bond at the carboxy end -->activated by enteropeptidase (secreted as part of pancreatic juice into duodenum)
T3 and T4 not secreted enough causes
Hypothyroidism -A deficiency of iodine or inflammation of the thyroid may lead to this -results in leathery, weight gain, decreased body temp, slowed respiratory rate, and cold intolerance
Starch is hydrolyzed into maltose by enzymes in the: I. salivary glands II. brush border III. pancreas
I and III -->starch is hydrolyzed into maltose by two enzymes: -salivary amylase (salivary glands) -pancreatic amylase (pancreas)
What is the genotype for type A blood
IAIA or IAi
What is the genotype for type AB blood
IAIB
What is the genotype for type B blood
IBIB or IBi
How does jaundice occur?
If liver is unable to process of excrete bilirubin (due to liver damage, excessive red blood cell destruction, or blockage of the bile ducts)
Gastrulation
In animal development, a series of cell and tissue movements in which the blastula-stage embryo folds inward, producing a three-layered embryo, the gastrula. >>three layers= meso-, ecto- and endoderm -Results in a thin layered tube forming in middle -the membrane invagination = the archenteron -the opening of this invagination is called the blastopore --> in deuterostomes (such as humans), the blastopore becomes the anus -in protostomes (ex: snail, crab, worm) it develops into the mouth
Where are pyloric glands found?
In the lower part of the stomach near the antrum and pylorus
Where are gastric glands found?
In the upper part of the stomach near the fundus and body (so maybe like upper 3/4)
muscle fatigue
Inability of muscle to maintain its strength of contraction or tension; may be related to insufficient oxygen, depletion of glycogen, and/or lactic acid buildup
trypsinogen
Inactive form of trypsin (hydrolyzes specific peptide bonds) -->activated by enterokinase --> cleaves chymotrypsinogen to chymotrypsin (secreted in pancreatic juice)
extensor muscle
Increases the angle across a joint (straightens a limb at a joint) ex: triceps brachii
Adrenal medulla
Inner part of the adrenal glands -secretes catecholamines: epinephrine and norepinephrine -deal with flight or fight response -the short term response to stress Epinephrine: -increases glucose break down (gluconeogenesis) in liver and muscles -increases basal metabolic rate Both (Epi and norepinephrine): -increase heart rate -dilate bronchi -shunt blood flow to muscles and heart and lungs -and away from the digestive system and skin >>deal with short term stress response while cortisol deals with long term response -cortisol increases the production of catecholamines as a long term response
Muscle cells are connected by ______
Intercalated discs: ~ Coordinate ventricular contraction ~contain gap junctions that directly connect the cytoplasms of adjacent cells --->this makes it so ions can flow easily through one cell to increase the ability for action potentials to spread btw cells
juxacrine signaling
Involve one cell directly stimulating receptors in an adjacent cell. -Do not involve diffusion
How does epinephrine increase contraction rate in the heart muscles
It increases the intracellular calcium levels within cardiomyocytes
How does the kidney regulate blood pH?
It regulates hydrogen (H+) and bicarbonate ions (HC03-) pH low --> excretes more H+ and reabsorbs bicarbonate pH high --> excretes more (HCO3-) increase reabsorption of H+ -->takes longer to act then the respiratory system but it also more effective
Path of urine from kidney to exiting body
Kidney --> ureter --> bladder --> Urethra
Which of Mendel's laws is contradicted by the existence of linked gene?
Law of independent assortment (2nd law)
The pharynx is connected to?
Leads from mouth and posterior nasal cavity and connects to both the esophagus and larynx, which is part of the respiratory tract
What is reabsorbed and or secreted in the collecting duct
Lets water leave (be reabsorbed) but amount it is permeable to water varies based on how hydrated you are --> Also can let out salts depending on conditions ->responds to both aldosterone and ADH dehydrated -> very permeable ->lots of water reabsorbed -> concentrated urine hydrated -> slightly permeable ->little water reabsorbed -> dilute urine
Agranulocytes are important in immune system for...
Leukocytes: -the specific immune response -targeted fight against particular pathogens -some are primary responders -some serve as a memory bank Monocytes: -phagocytize foreign matter -in blood monocyte but once in the tissue called macrophages
what is a gene locus
Location of a gene on a chromosome
Langherhans cells
Location: Stratum Spinosum Function: Macrophages that help activate the immune system APCs that present antigen to T-cells
Viral Life Cycle: Lytic and lysogenic cycles
Lytic cycle: -bacteriophage maximizes use of the cells machinery with no regard for survival of host -cell swells with new virions and lyses **viruses in this cycle are called virulent Lysogenic cycle: -virus integrates into the host genome if it doesn't lyse the bacterium --> as a provirus or prophage -in this case the virus is replicated along with the bacteria -can also leave the genome again due to environmental factor
Gonad endocrine overview
Males: -gonadotropins LH and FSH(post pit) act on the testes and cause to secrete testosterone -testosterone causes sexual differentiation of male during gestation and matinee of secondary sex characteristics Females: -LH and FSH (post pit) cause ovaries to secrete estrogen and progesterone -estrogen helps develop the female reproductive organs and helps promote development of secondary sex traits -both steroid hormones are also involved in maintaining the menstrual cycle and pregnancy
Viral Life Cycle: Progeny release
Many ways progeny can be released: 1) viral invasion causes cell death, resulting in viruses spilling out 2) The host cell may lyse as a result of being filled with an extremely large number of virions (lysis is a disadvantage for the virus bc it can no longer use the host cell) 3) virus can leave the cell by fusing with the plasma membrane process is called extrusion **in this case the virus is in the productive cycle
mechanical digestion vs chemical digestion
Mechanical digestion involves physically breaking the food into smaller pieces. Mechanical digestion does not break chemical bonds Chemical digestion involves breaking down the food into simpler nutrients that can be used by the cells. Chemical digestion is the enzymatic cleavage of chemical bonds such as peptide bond for AAs or glycosidic bond for starches
mentation
Mental activity of a patient ex: increased ammonia in the blood affects mentation
secretion function of the kidney
Movement of solutes from blood to filtrate anywhere besides Bowman's capsule ->nephron can secrete salts, acids, bases, and urea directly into the tubule by active or passive transport
filtration function of kidney
Movement of solutes from blood to filtrate at bowman's capsule
stabilizing selection
Natural selection that favors intermediate variants by acting against extreme phenotypes ex: human birth weight
polymorphisms
Naturally occurring differences in form between members of the same population
peripheral nervous system
Nerve tissues and fibers that are outside of the brain and spinal chord -includes 10 of the 12 cranial nerves -connects the CNS to the rest of the body -can be divided up into the somatic (voluntary) and autonomic (involuntary) nervous systems *the autonomic can then be further divided into the parasympathetic (rest and digest) and sympathetic (fight or flight) NS
Unconscious patient rushed to ER, what type of blood should she receive?
O- Because the blood has no surface antigens; no A or B makes it type O and no Rf makes it type O-
Gas exchange at the alveoli
Occurs bc blood arriving in pulmonary arteriole has a high partial pressure of CO2 and low partial pressure of oxygen -->therefore each gas moves down their concentration gradients (CO2 out and O2 in) -relies on simple diffusion -no energy is required
clonal selection
Only B cells that bind to the antigen with high affinity will survive. They go on to proliferate and become plasma cells or memory cells --->B-cells that do not are killed off
P vs. F1 vs. F2 generations
P=1, F1 = 2, F2 = 3 If your grandparents are the P generation then your parents are the F1 generation and you and your siblings are the F2 generation
A young women presents to the ER with a broken hip and yet has had to trauma to the bone. Her blood calcium levels are above the normal range. What tissue is responsible for these findings?
Parathyroid --> Her high calcium blood levels are due to an increase in bone resorption which causes her bones to be more fragile -->Parathyroid hormone (PTH) causes calcium release from the bone -->if this women has a parathyroid tumor or overactive parathyroid gland it could increase PTH levels and then increase the bone being reabsorbed even when calcium levels in blood are already high
Autonomic nervous system
Part of PNS that controls involuntary activity of visceral muscles and internal organs and glands. -regulates heartbeat, body temp, digestion, respiration, and glandular secretions. -divided in the sympathetic and parasympathetic to control rest and digest and fight or flight response **different from the somatic nervous system bc the autonomic nervous system contains two neurons in the peripheral part: -two motor neurons work in series to transmit messages from the spinal chord. The first neuron (preganglionic neuron) is from the spinal chord to the autonomic ganglia and the second neuron (post ganglionic neuron) is from the autonomic ganglia to the target tissue. -This is different from the somatic nervous system where one motor neuron goes directly from the spinal chord to the muscle without synapsing at any ganglia mid way.
chyme
Partially digested, semiliquid food mixed with digestive enzymes and acids in the stomach.
What enzyme breaks down clots
Plasmin which is generated from plasminogen --> Cuts up links between fibrin network
The axial skeleton
Portion of the skeletal system that consists of the skull, rib cage, vertebral column, and hyoid bone (small bone on anterior neck used for swallowing) -axial skeleton provides the basic central framework for the body
convergent evolution
Process by which unrelated organisms (no recent common ancestor) independently evolve similarities when adapting to similar environments ex: fish and dolphins
Necrosis
Process of cell death in which the cell dies as a result of injury -internal substances can be leaked causing harm to nearby tissues
All veins carry deoxygenated blood except for?
Pulmonary and umbilical veins
the pathway of blood starting at the right atrium (with valves included)
RA -- tricuspid valve-->RV--pulmonary valve-->pulmonary artery-->lungs-->pulmonary veins-->LA--mitral valve-->LV--aortic valve-->aorta--> arteries-->arterioles-->capillaries-->venules-->veins-->venae cavae-->RA
recombination frequency
Recombination frequency (θ) is the frequency with which a single chromosomal crossover will take place between two genes during meiosis. A centimorgan (cM) is a unit that describes a recombination frequency of 1% -->if two genes are 12 cM apart then they will only experience crossing over 12% of the time so would only expect to see recombination of these two genes in 12% of the gametes
Rh factor
Refers to the presence or absence of the Rh antigen on red blood cells. Rh- means you have the D allele Rh+ means you do not have the D allele -->If you are Rh+ and have type O blood you are O+ --> If you are Rh- and have type AB blood you are AB-
order of structures in the nephron
Renal corpuscle (Bowman's capsule and glomerulus) -->proximal convoluted tuble--> descending limb of loop of henle --> ascending limb of loop of henle --> distal convoluted tuble --> collecting duct
Griffith's experiment
Reported in 1928 by Fredrick Griffith, was the first experiment suggesting that bacteria are capable of transferring genetic information through a process known as transformation >>rough strain = nonvirulent smooth strain = virulent heat killed smooth strain = nonvir rough strain and heat killed smooth strain = virulent -->bc the rough strain was able to become virulent when mixed with the dead smooth strain he believed that the rough nonvirulent bacteria must have acquired the ability to form smooth capsules from the dead virulent bacteria -->transformation
adaptive immune system
Respond to specific antigens; Responds by remembering signature molecules, called antigens, from pathogens to which the body has previously been exposed >Faster response when sees the pathogen again bc has immunological memory >response is variable and depends on identity of the pathogen Two divisions: -humoral (B-cell) -cell-mediated (T-cell)
Path of electrical conduction in the heart
SA node > atria > AV node > bundle of His > Purkinje fibers > ventricles
How are fats absorbed from the GI tract?
Short chain fatty acids: ->follow same path as cabs and AAs. They diffuse directly into intestinal capillaries, but don't require transporters bc nonpolar Larger fats, glycerol, and cholesterol: ->move into the intestinal cells and then are reformed as triglycerides and then packaged into cylomicron ->cholesterol is esterfied and then packaged into cylomicron Vitamins: fat soluble (A,D,E,K): dissolve directly into cylomicron water soluble: taken up with AAs, carbs, and water across endothelial cells and enter directly into blood
How does the body regulate pH?
Short term: -brain senses the change -If low pH(acidic) ->increase respiratory rate -If high pH (basic) -> slow respiratory rate Long term: -Kidneys play a role -modulate secretion and reabsorption of acid and base within the nephron
Steps in a motor (efferent) neuron telling a myocyte to contract (up to point where Ca2+ is released)
Signal travels down the neuron until it reaches the nerve terminal (synaptic bouton) -there it releases acetylcholine into the synapse -acetyl choline binds receptors in the sarcolemma and causes depolarization -depolarization triggers an action potential which spreads down the sarcolemma to the T-tubules and from the T-tubules to the sarcoplasmic reticulum -this causes Ca2+ to be released
slow twitch vs fast twitch muscle fibers
Slow-twitch (type 1) oxidative fibers contract at a slow rate due to the lesser frequency at which the myosin heads hydrolyze ATP during each contractile cycle. These fibers produce ATP via aerobic respiration. Therefore, they contain many mitochondria that use oxygen in the electron transport chain to produce large amounts of ATP (energy), making these fibers more fatigue resistant. Type 1 fibers receive oxygen from their extensive capillary networks and high concentrations of myoglobin. Fast-twitch fibers achieve more rapid contraction rates (complete more contractile cycles) than slow-twitch fibers because they can hydrolyze ATP much faster. These fibers are classified as follows: Fast glycolytic (type 2X) fibers rely primarily on nonoxidative (anaerobic) glycolysis for ATP production. Accordingly, these fibers fatigue more easily due to the acidosis caused by H+ accumulation from anaerobic ATP hydrolysis. Because type 2X fibers generally contain very few mitochondria and require much less oxygen than oxidative fibers, they exhibit low myoglobin concentration and less extensive capillary networks. Fast oxidative-glycolytic (type 2A) fibers use both oxidative (ie, aerobic respiration) and nonoxidative processes (ie, anaerobic glycolysis) to generate ATP, making them moderately susceptible to fatigue. Like type 1 fibers, these fibers also receive oxygen from abundant myoglobin reserves and extensive capillary networks.
Cell specification versus determination
Specification: -cell is reversibly designated to a specific cell type Determination: -the commitment of a cell to a particular function in the future -But cells still haven't produced what they need to to carry out their specific functions (this occurs during differentiation) Determination can occur through: -mRNAs and protein molecules that were asymmetrically distributed between daughter cells -secretion of specific molecules in nearby cells -->these molecules are called morphogens
Immune tissues in the body
Spleen: site of blood storage and also B-cells can be activated here Thymus: small gland above the pericardium where T-cells mature Lymph nodes: A place where immune cells communicate and pair up Gut associated lymphoid tissue (GALT): -tonsils -adenoids -Peyer's patch in the small intestine -appendix
What causes filtrate to move from blood into bowman's space?
Starling forces -Hydrostatic pressure in the blood is much higher than in bowman's space so pushes out blood (20%) -The osmotic pressure is higher in the nephron and so works against blood moving in, but its much smaller than the hydrostatic pressure so the blood still moves into bowman's space
law of independent assortment (Mendel's second law)
States that the inheritance of one gene does not affect the inheritance of another gene -->recombination during prophase I allows for the inheritance of one gene to be independent of inheritance of others -->this law is contradicted to a degree by linked genes
frequency summation
Strengthening of contraction that results when the stimuli are so frequent that muscle cannot fully relax. The stronger contraction is due to the incorporation of more muscle fibers.
each alveoli is coated in
Surfactant -a detergent that lowers the surface tension and prevents the alveolus from collapsing in on itself -also surrounded by capillaries that carry CO2 to them and O2 away
temporal summation versus spatial summation
Temporal summation: multiple signals are received by the axon hillock over a short period of time Spatial summation: The additive effects based on the number and location of the incoming signals. So it lots of inhibitory signals and only a few excitatory signal will be inhibitory.
White matter and gray matter in the brain
The CNS is the brain and spinal chord >The brain consists of white matter and grey matter -white matter = axons encased in myelinated sheaths -grey matter = unmyelinated cell bodies and dendrites *in the brain the white matter lies deeper than the grey matter
regeneration capacity
The ability of an organism to regrow certain parts of the body -some species can undergo complete regeneration where the tissue is grown back and functions at the same capacity -Humans mostly go through incomplete regeneration which is where the newly formed tissue is not identical in structure or function >liver has a high regenerative capacity >heart has none >kidney has some
Differentiation
The cell undergoes changes in structure, function and biochemistry that cause the cell to develop into its determined cell type -cells that have not yet differentiated = stem cells -Cells up to the 16-cell embryo stage are totipotent stem cells bc can become anything -cells in three germ layers are pluripotent-> can be any cell type other than the placenta -cells continue to specialize and are multipotent -> can differentiate into many different types of cells within a particular group ex: hematopoietic stem cells can differentiate into any of the blood cells
Prophase I
The chromosomes condense, and the nuclear envelope and nucleoli breaks down and spindle apparatus forms -homologous chromosomes come together in a process called synapsis -at this point each chromosome consists of two daughter chromatids -so each synaptic pair has four chromatids (called a tetrad) -homologous proteins are held together by a group of proteins called the synaptonemal complex -The point where the homologous chromosomes overlap is called the chiasmata and they may break here and exchange pieces of DNA -this process is called crossing over -linkage can occur if genes are closer together and so more likely to go through recombination together and be inherited together
Vital Capacity (VC)
The difference between the minimum and maximum volume of air in the lungs (TLC-RV)
Why doesn't the diastolic blood pressure drop to zero?
The elasticity of the larger arteries allows the body to maintain a sufficient blood pressure when the ventricles are relaxed
The founder effect
The founder effect is a special case of genetic drift, occurring when a small group in a population splinters off from the original population (often due to a barrier being formed) and forms a new one. The new colony may have less genetic variation than the original population, and through the random sampling of alleles during reproduction of subsequent generations, continue rapidly towards fixation. This consequence of inbreeding makes the colony more vulnerable to extinction
Both segregation or homologous chromosomes and independent assortment of alleles increase ______?
The genetic diversity of the gametes and therefore the genetic diversity of the offspring
The semi-permeable membrane of the dialysis machine functions in a manner most analogous to what part of the kidney?
The glomerulus --> which functions like a sieve, allowing the filtration of small molecules while blocking the filtration of the plasma proteins
Nerves control the force of contraction based on _____?
The number f motor units they recruit to respond
Hemacrit
The percentage of a blood sample that is RBC's normal numbers: male= 41-53% females= 36-46%
ADH is secreted in response to
The posterior pituitary secretes ADH in response to: -low blood volume (via baroreceptor) or -increased blood osmolality (via osmoreceptor) --> at the collecting duct ADH increases its permeability to water. Lets in more water from the filtrate in the nephron which results in: increased water retention = increased blood volume = higher blood pressure
_______ triggers the small intestine to secrete enzymes
The presence of chyme
Blastulation
The process by which a morula develops into a blastula with a fluid-filled cavity called a blastocoel. ->Morula = solid ball of cells ->Blastocoel or blastocyst (in mammals): -made of two cell groups: trophoblast and inner cell mass -trophoblast cells surround the blastocoel and give rise to the chorion and the placenta -inner cell mass gives rise to the organism itself
Implantation
The process by which the blastula moves through the fallopian tubes and into the uterus where it burrows into the endometrium -Trophoblast cells create and interface between maternal blood supply and embryo -Trophoblast cells give rise to the chorion: an extraembryonic membrane that becomes the placenta -Trophoblasts form chorionic villi: fingerlike protections that penetrate the endometrium and facilitate gas exchange -embryo is connected to placenta by umbilical chord -before the placenta forms the embryo is supported by the yolk sac -The allantois is an extra embryonic membrane that is involved in fluid exchange between the embryo and the yolk sac -allantois is surrounded by the amnion which is a thin tough membrane filled with fluid. Serves as a shock absorber.
X chromosome
The sex chromosome found in both men and women. Females have two X chromosomes; males have one. An X chromosome from each parent produces a female child. -The Ova can only carry the X chromosome where as sperm can carry either the X or Y chromosome -The X-chromosome carries a sizable amount of genetic information -Males with a mutation on the X chromosome will have to carry it where as females can be heterozygous for it -most X-linked disorders are recessively inherited and therefore females express the disorder far less than frequently than males
inclusive fitness
The sum of an individual's own reproductive success plus the effects the organism has on the reproductive success of related others. -explains why altruistic behavior exists in certain species
Absorption (from GI tract)
The transport of products of digestion into the circulatory system so they can be distributed to the cells and tissues of the body
umbilical chord
The umbilical chord is an organ that is derived from extra embryonic embryonic membranes (yolk sac and allantois) in placental mammals and connects the embryo to the placenta. -made up of two arteries and one vein -vein carries freshly oxygenated blood rich with nutrients to the placenta -arteries carry deoxygenated blood and waste to the placenta for exchange
What nerve slows the heart
The vagus nerve through parasympathetic activity
hypothalamus and posterior pituitary interaction
Through neurons from the hypothalamus that send their axons directly to the posterior pituitary!! -stimulates it to release: i)oxytocin -stimulates uterine contractions during labor -and milk letdown during lactation -also involved in bonding ii)Antidiuretic hormone (ADH) -also called vasopressin -increases water reabsorption in the collecting dicts of the kidney -so its secreted when high plasma osmolarity -or high solutes in the blood
The maturation of T-cells is facilitated by what hormone?
Thymosin
Viral Life Cycle: Translation and Progeny assembly
Translation of viral genetic material must occur in the correct location inside the cell: -DNA viruses must enter nucleus to be transcribed into mRNA, then mRNA goes to ribosomes to be translated -positive sense RNA viruses stay in cytoplasm and use ribosomes to make proteins -Negative sense RNA virus first uses RNA replicase to make complementary RNA strand which can then be translated into proteins -retroviruses are first formed via reverse transcriptase and then go to nucleus and incorporate into host cell genome -once viral genome is replicated its packaged into capsid protein (made from ribosomes in host cell) **note that a viral genome must be returned t its original form before packaging [ex: retroviruses must transcribe new copies of their single stranded DNA from the DNA that entered the host genome]
Which structure does Ca2+ bind to in the sarcomere?
Troponin -->which then causes tropomyosin to move and open up the myosin binding site on actin **remember this bc calcium has charge of 2+ and troponin has 2 ns
Twins
Twins occurs by two different mechanisms: 1) Dizygotic (fraternal) twins: -form from fertilization of two different eggs released during one ovulation cycle by two different sperm -each zygote has its own placenta, chorion, and amnion 2)Monozygotic (identical) twins: -form when a single zygote splits in two -genomes of offspring are identical -If division is incomplete, conjoined twins results >classified by the number of structures they share: -same anion and chorion = Monochorionic/monoamnionic -different anion same chorion = dichorionic/monoamnionic -different anion and chorion = dichorionic/diamnionic
parallel evolution
Two related species that have made similar evolutionary adaptations due to living with similar environmental pressures after their divergence from a common ancestor ex: two desert rodents have same coat color and size due to constraints of the dry climate
Which blood type is the universal donor?
Type O (negative- doesnt have Rh factor) --> because type O has no antigens on the surface of their RBCs so if given to another person will not cause an immune response
What two vitamins do the bacteria of the gut produce?
Vitamin K - essential for the production of clotting factor Biotin (vitamin B7) - coenzyme for many metabolic enzymes
incomplete dominance (genetics)
When a heterozygote expresses a phenotype that is an intermediate between the two homozygous genotypes ex: RR= red rr= white Rr= pink
When do you get the strongest contraction of a muscle?
When all fibers in a muscle are stimulated to contracted simultaneously by the nerve
Antagonistic pairs of muscles
When one contracts the other relaxes ex: biceps brachii and triceps brachii biceps contract and triceps relax = elbow flexed
self-tolerance
When suppressor T-cells turn off self reactive lymphocytes to prevent an autoimmune disease from occurring >the term generally refers to the immune system not attacking itself > If you are lacking self tolerance then you will have an autoimmune disease
Unless stated otherwise, assume all sex-linked traits on the MCAT are ...?
X-linked recessive
From zygote to gastrula, what are the various stages of development?
Zygote-> 2,4,6,8, 16-cell embryo-> morula ->blastula-> gastrula
prezygotic isolation
a barrier to successful breeding that occurs before fertilization, such as differences in mating time or behavior -temporal isolation (breeding at different times) -ecological isolation (living in different niches) -behavioral isolation (lack of attraction due to different mating displays ect) -reproductive isolation (incompatibility of reproductive anatomy) -gametic isolation (intercourse can occur but fertilization can not occur)
Inversion mutation (chromosomal)
a chromosome rearrangement in which a segment of a chromosome is reversed end to end
innate immune system
a collection of nonspecific barriers and cellular responses that serve as an inborn first and second line of defense against pathogens >Response is faster than adaptive immunity when the pathogen is unknown >all or none response
Bile
a digestive juice secreted by the liver and stored in the gallbladder -->made up of bile salts, pigments, and cholesterol
titin
a protein that positions the myosin filament to maintain equal spacing between actin filaments --prevents excess stretching of the muscle
complete dominance (genetics)
a relationship in which one allele is completely dominant over another -->So that the presence of one dominant allele will completely mask the recessive allele if present
bottleneck effect
a sharp reduction in the size of a population due to environmental events (such as famines, earthquakes, floods, fires, disease, or droughts) or human activities (such as genocide). Such events can reduce the variation in the gene pool of a population; thereafter, a smaller population, with a smaller genetic diversity, remains to pass on genes to future generations of offspring through sexual reproduction.
Primary role of the large intestine
absorb water -->concentrates the remaining material to form feces --> however absorbs less water than the small intestine
niche
a specific environment, including habitat and resources and predators fro which a species is specifically adapted
Tetanus
a sustained muscular contraction resulting from a rapid series of nerve impulses and that are so often that the muscle is unable to relax at all
vector
a virus that carries genetic material from one bacterium to another
Thin filaments are composed of
actin, troponin, tropomyosin
How are simple sugars and amino acids transported into the small intestine cells?
active transport and facilitated diffusion some are transported in with Na+ which helps transport bc Na+ is being pumped out of cell by Na/K pump
An action potential is often described as an ___________ response
all or nothing -This means that whenever the threshold membrane potential is reached, an action potential with a consistent size and duration is produced.
Teratogens
agents, such as chemicals and viruses, that can reach the embryo or fetus during prenatal development and cause harm ex: alcohol, prescription drugs, bacteria, viruses, chemicals
common carrier protein for steroid hormones
albumin
proteins the liver makes that are necessary for body function
albumin and clotting factors
Name the few substances that the stomach does absorb
alcohol and aspirin -->mostly responsible for digestion, not absorption
peptidases secreted by the duodenum
amniopeptidase: removes the N-termial amino acid from a peptide Dipeptidases: Cleaves the peptide bond of dipeptides to release free amino acids
Law of segregation is seen carried out during what phase of the cell cycle?
anaphase I od meiosis -->when the separation of homologous chromosomes occurs ---> by separating these chromosomes into different cells, each gamete carries only one allele for any given trait
articular cavity
another name for joint cavity -->the space in between bones in a moveable joint
Thrombocytes
another name for platelets --> which are cell fragments or shards secreted by cells in the bone marrow called megakaryocyctes --> assist in blood clotting --> present in high concentrations (150,000 - 400,000 per uL of blood) --> stimulated to develop in the bone marrow by thrombopoietin which is secreted from the liver and kidney
synergistic muscles
any two muscles whose contraction produces the same movement -->work together to accomplish the same function
Three major types of blood vessels
arteries, capillaries, veins
smaller, muscular arteries are called
arterioles
Which vessel types act like resistors
arterioles and capillaries
colon parts and function
ascending, transverse, descending, sigmoid function: absorb water and salts
epiphyseal (growth) plate
at the internal edge of the epiphysis cartilaginous structure site of longitudinal growth filled with mitotic cells prior to puberty close at puberty - and growth is halted
The circulatory system is under control of the _______ nervous system
autonomic -->when scared the sympathetic nervous system speeds up the heart rate -->When relaxed the parasympathetic nervous system slows down the heart rate via the vagus nerve
In animals, autosomal cells are _________, where as germ cells are _____
autosomal--> diploid (2n) meaning they have two copies of each chromosome (46) germ --> hapliod(n) only 1 copy of each chromosome (23)
Pancreatic juice contains
bicarbonate (neutralizes) enzymes: -Pancreatic amylase -trypsinogen -chymotrypsinogen -(pro)carboxypeptidases A and B -pancreatic lipase
major pigment in bile? Where does it come from?
bilirubin -->a byproduct of the breakdown of hemoglobin -->liver attaches the bilirubin to a protein (conjugated)
What is a portal system
blood must flow through two capillary beds in series before returning to the heart three in the body: 1) The hypophyseal portal system (connects hypothalamus and anterior pituitary) 2) The hepatic portal system (connects the gut tube and the liver) 3) The renal portal system (glomulerus and vasa recta)
The cavities between trabecular is filled with?
bone marrow
appendicular skeleton
bones of the limbs, the pectoral girdle, and pelvis
tropic hormones usually originate in the
brain or anterior pituitary
common second messengers
cAMP, IP3, calcium
hormone that promotes bone formation
calcitonin -released by the parafollicular cells of the thyroid when calcium levels in the blood are high promotes the formation of bone which in turn lowers calcium blood levels
Where does chemical digestion start for carbohydrates, fats and proteins?
carbs + fats ---> mouth proteins---> stomach
label the bones of the hand
carpals metacarpals phalanges
Fetal skeletons are mostly made up of
cartilage -->gives them extra flexibility when they are growing in a confined space
cartilage vs.bone
cartilage is more flexible -however it is avascular and not innervated -means it doesn't really regrow
lactase
catalyzes the hydrolysis of lactose to glucose and galactose. ->brush boarder enzyme
sucrase
catalyzes the hydrolysis of sucrose into glucose and fructose ->brush boarder enzyme
three parts of the large intestine
cecum, colon, rectum
Glial cells (4 kinds)
cell in the nervous system that support, nourish, and protect neurons -also called neuroglia Types to know for the MCAT: -Astrocytes: nourish neurons and form the blood-brain barrier -Ependymal cells: line the ventricles of the brain and produce cerebrospinal fluid -Microglia: are phagocytic cells that ingest and breakdown waste products and pathogens in the CNS -Oligodendrocytes(CNS) and schwann cells (PNS) produce myeln around axons
label the categories of vertebrae
cervical(7) thoracic(12) lumbar(5) sacrum coccyx
mastication
chewing -->part of mechanical digestion
bile salts are derived from
cholesterol
The gallbladder is a common site for ____ or ____ stone formation
cholesterol or bilirubin -->common bc bile is so concentrated there -can block off the biliary tree and cause inflamation of gallbladder -or can get stuck right before entering duodenum and block off pancreatic duct-->leads to pancreatitis
Thrombus formation
clot formation
yellow bone marrow
composed primarily of fat and is relatively inactive
complete blood count (CBC)
comprehensive blood test that includes red blood cell count (RBC), white blood cell count (WBC), hemoglobin (Hgb), hematocrit (Hct), white blood cell differential, and platelet count
cretinism
condition of congenital hypothyroidism (low T4 and T3) in children that results in a lack of mental development and dwarfed physical stature; the thyroid gland is either congenitally absent or imperfectly developed
Hershey-Chase Experiment
confirmed that DNA is the genetic material because only radiolabeled DNA (phosphorus atoms) could be found in bacteriophage-infected bacteria
Joints are made of ________. And the two types of joints are:
connective tissue 2 types: -immovable -movable
bone is a _________ derived from embryonic _______
connective tissue mesoderm
interstitium
connective tissue surrounding the nephron --->also can be used in other context (?)
When antigen binds an antibody on the surface of a mast cell it causes
degranulation -->the mast cell releases histamine and causes inflammatory allergic response
hypodermis
contains fat and fibrous tissue -layer of skin below the dermis
A-band
contains the thick filaments in their entirety, including any overlap with thin filaments
Sweating steps
controlled by autonomic NS -->occurs when body temp rises above temp determined by the hypothalamus --> then postganglionic sympathetic neurons use achetalcholine to innervate sweat gland so secretes water and ions onto skin -->water evaporates and reaction takes away heat from body --> also arterioles vasodilation brings more blood to skin to increase heat lost
chymotrypsinogen
converted to chymotrypsin by trypsin -->hydrolyzes specific peptide bonds (secreted as part of pancreatic juice into duodenum)
region of kidney with lowest solute concentration
cortex
articular cartilage
covers the surfaces of bones where they come together to form joints -->in a movable joint
Molecules that control the cell cycle
cyclins and cyclin deponent kinases(CDKs) -CDKs require presence of the right cyclins to be activated -during cell cycle the cyclins increase and decrease at various points -the cyclins bind to CDKs, creating a complex that can then phosphorylate transcription factors -These transcription factors are now active and can promote the transcription of genes required for the next stage in the cell cycle
sarcoplasm
cytoplasm of a muscle cell
inborn errors of metabolism
deleterious mutations that affect the genes required for metabolism ex: phenyketonuria (PKU) person can't breakdown phenyalanine
Opening the capillary beds will cause what changes to occur
decrease the vascular resistance --->leading to increased cardiac output
Pacinian corpuscles
deep pressure and vibration receptors (located in dermis)
renal hilum
deep slit in the center of the kidney's medial surface --> Where the renal artery, vein and ureter enter and exit through
reticular layer
deepest layer of the dermis --> made up of denser, more irregular connective tissue
deleterious mutation
describes mutations that are harmful to an organism
hemolysis
destruction of red blood cells --> occurs if you are given a blood type that your body makes antigens for
muscular lining of the bladder
detrusor muscle --> contracts due to parasympathetic activity (activated by stretch receptors in the bladder)
Disaccharidases
digest disaccharides to monosaccharides -Maltase digests maltose -isomaltase digests isomaltose -lactase digests lactose -sucrase digests sucrose >>lack of them can cause bloating diarrhea, and flatulence >>type of brush-boarder enzyme secreted by duodenum
alimentary canal
digestive tube that extends from the mouth to the anus
only portion of nephron that can produce urine thats more dilute than the blood
diluting segment of loop of henle
Isomaltase
disaccharidase/ brush boarder enzyme ->digests isomaltose into two glucose molecules made in intestinal glands works in the duodenum
All exocrine cells secrete their products into ______
ducts
At the arteriole end of a capillary bed there is a net _____ of water
eflux --> water leaves -because hydrostatic pressure is greater than oncotic pressure
Genes that are very weakly linked are expected to have a recombination frequency close to what?
either at or close to 50%
bile salts function
emulsify fats and cholesterol into micelles -->can do this because have both hydrophobic and hydrophilic regions >keeps the fats in solution and then increases their surface area by placing the into micelles (mechanical digestion) --> fats would not be accessible to pancreatic lipase without bile salts
Scientists studying evolution in yeast found that a certain species underwent a reduction in chromosome number with no loss of coding information. Given this, which of the following mechanisms best explains how this reduction in chromosome number may have occurred?
end-to-end (telomere-to-telomere) fusion of two chromosomes and inactivation of one of the centromeres. This fusion would initially generate a larger chromosome with two centromeres, and inactivation of one of these centromeres would produce a single new chromosome, reducing the chromosome number in the cell by one (Number I). breakage of a chromosome at the centromere and fusion of each chromosomal portion to the ends of other chromosomes. This initial breakage would result in two individual chromosomal portions. Fusion of these portions to other chromosomes would cause the original chromosome to be lost, also reducing the overall chromosome number in the cell by one (Number II).
All blood vessels are lined with
endothelial cells
acromegaly
enlargement of the extremities caused by excessive secretion of growth hormone after puberty -long fingers and toes and head bones -gigantacism is caused by excess GH before puberty
What system governs the function of the gastrointestinal system
enteric nervous system --->triggers peristalsis The enteric nervous system is heavily regulated by the autonomic nervous system
Retroviruses
enveloped single stranded RNA viruses -carry the enzyme reverse transcriptase which synthesizes DNA from a single stranded RNA -the DNA then integrates into the host cells own DNA -makes it so the host cell is infected indefinitely -ex: HIV
Layers of the skin
epidermis, dermis, hypodermis
Of the three structural parts of bone (diaphysis, metaphysis, epiphysis) which part contributes most to linear growth?
epiphysis -->growth plates are found here that contribute to linear growth
Four types of tissue
epithelial, connective, muscle, nervous
cellular portion of blood
erythrocytes, leukocytes, platelets
entergastrone
ex. secretin hormone that slows motility through the digestive tract gives more time for the digestive enzymes to act on the chyme
polydipsia
excessive thirst -is a symptom of diabetes
polyuria
excessive urination -symptom of diabetes
Exoskeleton vs. Endoskeleton
exoskeleton: -encase the whole organism -protects the soft tissues well -but have to be shed and regrown when the organism grows -seen in insects endoskeletons: -don't protect the soft tissue as well -but much better at accommodating growth -humans have these
label the bones of the leg
femur patella tibia fibula
What stabilizes a blood clot
fibrin
lymphatic system functions
fluid recovery, immunity, lipid absorption
blood pressure is a measure of the
force per unit area exerted on the wall of the blood vessels
disruptive selection
form of natural selection in which a single curve splits into two; occurs when individuals at the upper and lower ends of a distribution curve have higher fitness than individuals near the middle >>facilitated by the existance of polymorphisms ex: large or small beaked finches on Galapagos bc large beaks could crush open larger seeds and smaller beaks could reach inside certain fruits and seeds to get nutrients -->no advantage to the medium beak
Hematopoiesis
formation of blood cells -occurs in the bone marrow and is triggered by hormones and growth factors -all originate from the precursor: hematopoietic stem cells. Leukocytes(WBC) divide into 2 types: 1)Granulocytes: have granules in their cytoplasms that contain toxic enzymes and chemicals. -neutrophils -eosinophils -basophils 2) Agranulocyte: include lymphocytes and monocytes -B- cells + T-cells (L) -Monocytes: phagocytic cells in the bloodstream. Become macrophages in tissues
red bone marrow
found in cancellous bone; site of hematopoiesis -->filled with hematopoietic stem cells which give rise to all the cells in the blood
How do the ventricles contract?
from the apex up **remember base of the heart is actually the top part
what provides the enzymes for the digestive tract
gallbladder, liver, pancreas, and salivary glands
In the PNS, cell bodies of neurons are grouped together and called _____, in the CNS cell bodies of the neurons are grouped together and called ____.
ganglion in PNS nuclei in CNS
point mutation
gene mutation in which a single base pair in DNA has been changed three types: -silent mutation -missense mutation -nonsense mutation
What hormones trigger stimulate feelings of hunger
glucagon --> secreted by pancreas ghrelin--> secreted by stomach and small intestine
Substances that are almost always reabsorbed by kidney
glucose, amino acids, vitamins, -->ADH and aldosterone can also alter the quantity of water reabsorbed within the kidney to maintain blood pressure
two types of cell walls in bacteria
gram positive and gram negative >>Gram positive: -envelope will absorb violent stain in a test and stain deep purple -consist of a thick layer of peptidoglycan(A.As and sugars) -also contains lipteichoic acid >>Gram negative: -very think -contains some peptidoglycan -these bacteria also have out membranes containing phospholipids and lipopolysaccharides(LPS) -LPS trigger our immune system response
sperm structure
head, midpiece, and flagellum i)Head -contains genetic material -covered by a cap called an acrosome -acrosome is derived from the golgi apparatus and is needed to penetrate the ovum ii)midpiece -generates ATP from fructose -filled with mitochondria that generates the energy iii)Flagellum -used for motility *once a male reaches sexual maturity during puberty, approximately 3 million sperm are produced per day for the rest of his life.
All blood cells are derived from ___________, which originate in the ________
hematopoietic stem cells, bone marrow
Arteries are highly _____ and ______
highly muscular and elastic -->Creates a tremendous resistance to the flow of blood -after they are filled with blood, the elastic recoil from their walls maintains the pressure and forces blood forward
Each human possesses two copies of each chromosome called _______ -->except for
homologues -->except for male sex chromosomes (in which there is only one X chromosome and one Y chromosome)
Tropic hormones
hormones that stimulate other glands to release their hormones ex: GnRH is a tropic hormone produced by the hypothalamus and it acts on the anterior pituitary -The pituitary then releases LH and FSH (two more tropic hormones) -LH then acts on the gonads to stimulate the release of testosterone (not a tropic hormone)
allele frequency
how often a form of a gene appears in a gene pool -If 7 out of 10 plants are purple then we say the dominant allele frequency is 70% or .7
label the bones of the arm
humerus ulna radius
Pancreatic amylase
hydrolyzes starch to maltose and dextrins (secreted in pancreatic juice)
pancreatic lipase
hydrolyzes the ester bond in lipids
excess T3 and T4 leads to
hyperthyroidism -can be caused by tumor or thyroid overstimulation -results in heightened activity, increased body temp, increased reparation and heart rate, heat intolerance, and weight loss
Under normal physiological circumstances the primary function of the nephron is to create urine that is ________ to the blood
hypertonic to the blood excretion of concentrated urine serves to limit water loss from the body and preserve the blood volume
system that connects the hypothalamus and anterior pituitary
hypophyseal portal system --blood vessel system
Another name for the pituitary
hypophysis
negative feedback loop of the stress response from the hypothalamus
hypothalamus releases CRF which causes anterior pituitary to release ACTH which leads to adrenal cortex releasing cortisol -then there are cortisol receptors on the hypothalamus and the anterior pituitary -cortisol binds and inhibits the hypothalamus from releasing CRF and the anterior pituitary from releasing ACTH
endocrine organs
hypothalamus, pineal gland, pituitary, the parathyroid, adrenal glands, testes, ovaries, and the pancreas Also the following organs are not considered endocrine organs bc its not their primary fan but they do have some endocrine fxn: kidneys, gastrointestinal glands, heart, and thymus
The two structures of the liver that communicate with the digestive system
i) Bile ducts (connect liver to gallbladder and small intestine) ii)hepatic portal vein (how liver receives blood from digestive tract)
Three ways to increase blood pressure
i) vasoconstriction (baroreceptors -sense degree of force on vessel wall) ii)ADH or vasopressin (chemoreceptors - sense high osmolarity) iii) Aldosterone (juxtaglomular cells of kidney - sense low perfusion)
ways to decrease blood pressure
i) vasodilatation (baroreceptors tell sympathetic nervous system to decrease the constriction) ii) ANP (peptide hormone released by atrial cells of heart - causes nephron to secrete salt and water to decrease BP) - but isn't that strong
Cell theory (4 tenants)
i)All living things are composed of cells ii)The cell is the basic functional unit of life iii)Cells arrises only from preexisting cells iv)Cells carry genetic information in the form a DNA. This genetic material is passed on from parent to daughter **Viruses violate number 3 + 4 so are not considered living organisms
duodenum secretes what?
i)brush-boarder enzymes ii)enteropeptidase iii) secretin iv) CCK
differential reproduction
if the change that results from a mutation is favorable, that change is more likely to pass on to the next generation -->and a change that is unfavorable is less likely to be passed on
What is the genotype for type O blood
ii
Viral Life Cycle
infection-->translation + progeny assembly--> progeny release-->lytic + lysogenic cycles
What causes varicose veins?
incompetent venous valves -->blood flows backwards and pools up and causes the vein to distend
How does aldosterone affect blood pressure?
increases blood pressure by increasing salt reabsorption (in DCT and collecting duct) and thus water reabsorption
How does ADH affect blood pressure?
increases it -->increases water reabsorbed from collecting duct which increases the volume of the blood which increases blood pressure
pancreatitis
inflammation of the pancreas -->caused by gallstones or excessive consumption of alc -->results from premature activation of pancreatic enzymes which can lead to auto-digestion of pancreatic tissue longterm result: -diabetes -reduced ability to digest fats and proteins
At the venule end of a capillary bed there is a net _____ of water
influx--> water enters -because oncotic pressure (the sucking pressure generated by the plasma proteins in the blood) is greater than the hydrostatic pressure
Mendel's second law of independent assortment
inheritance of one allele has no effect on the likelihood of inheriting certain alleles for other genes
Cardiac muscle contraction is _____ and so is innervated by the ______ nervous system
involuntary autonomic nervous system
Smooth muscle is responsible for _____ actions and so is controlled by the ________ nervous system
involuntary autonomic nervous system
Exhalation muscles
internal intercostals and abdominal muscles (if active) -If not active then it occurs through relaxation of the diaphragm and the external intercostals
Two types of digestion
intracellular and extracellular
Parts of small intestine primarily involved in absorption
jejunum and ileum
When blood osmolarity is low
kidney reabsorbes solutes and excretes water
What causes lactose intolerance?
lack of lactase (disaccharidase) --> means that bacteria in the small intestine hydrolyze the lastose and produce methane gas as a biproduct (flatulence and bloating) --> also, the undigested lactose increases the osmolarity of the stool and pull water in (diarrhea)
The epiglottis prevents food from going into the ____
larynx -->it is a cartilaginous structure that folds down to cover the laryngeal inlet
Human gestation
lasts about 280 days after last menstrual period, or 266 days after conception -divided into three trimesters
stratum granulosum
layer of the epidermis where the keratinocytes die and lose their nuclei
Resistance of vessels is based on what factors
length and cross sectional area increased length = increased resistance increased cross sectional area = decreased resistance
attach bone to bone at joints
ligaments
plasma
liquid portion of blood -->mix of nutrients, salts, respiratory gases, hormones and blood proteins
accessory organs of the digestive system
liver, gallbladder, pancreas
Adrenal glands
located on top of the kidneys -split into the cortex and medulla cortex: -outside layer -secretes corticosteroids: ->steroid hormones that can be divided into three classes; glucocorticoids, mineralcorticoids, and cortical sex hormones medulla: -inner layer -secreters catecholamines (amino acid hormones): -->epinephrine and norepinephrine -these deal with the sympathetic nervous system
Haversian canals
longitudinal channels (those with an axis parallel to the bone) contains BVs, nerve fibers, and lymph vessels
Weakness in the _____ causes GERD
lower esophageal sphincter
sphincter between the esophagus and stomach
lower esophageal sphincter (cardiac sphincter)
vasoconstriction of the afferent arteriole leads to
lower pressure of blood reaching glomeruli --> sensed by the adjacent juxtagomular cells --> secrete renin ...... leads to aldosterone being secreted which leads to increase in blood pressure
How does ADH affect blood osmolarity?
lowers it -->increases water reabsorption from the collecting duct --> makes the cell junction of the collecting duct leaky so more water leaves
partial pressure of oxygen in the lungs vs the tissue
lungs: 100 mmHg tissues: at rest--> 40 mmHg exercising --> 20 mmHg >>this means that when at rest the tissues only get 20% of the oxygen bound to heme but when exercising they get 70% of oxygen
germinal centers
lymph node location where B lymphocytes mature and proliferate
In the blood the cell is called a monocyte but once it enters the tissue it is called a
macrophage
Cells of the innate immune system
macrophages: Reside in certain tissues and become activated when a bacteria enters. Then they PHAGOCYTIZE the bacteria, next they DIGEST the bacteria and finally they PRESENT the antigens from it. Has both MHC class I and II. Dendritic cells: also professional antigen presenting cells so has both MHC class I and II. natural killer cells: Destroys cells that have been infected with pathogens. Recognizes the down regulation of MHC on infected cells and cancer cells granulocytes -Neutrophils: phagocytic cells of the blood and target bacteria. Can also detect a bacteria once it has been opsonized (marked with an antibody from a B-cell) -Eosinophils: fight against allergies and parasitic infections. When activated release histamine which results in vasodilation and increased leakiness of BVs -basophils: involved in allergic response (least populous in blood when no/low allergens) (releases histamine) -mast cells: also involved in allergic response but exist in tissues and mucous and epithelia not the blood (releases histamine)
Path of Pancreatic Juices
made in acinar cells --->pancreatic duct--> go through major and minor papillae --> duodenum
Functions of the cardiovascular system
maintenance of blood pressure, gas & solute exchange, coagulation, & thermoregulation
inbreeding
mating between two genetically related individuals -increases homozygosity
Total Lung Capacity (TLC)
maximum amount of air contained in lungs after a maximum inspiratory effort (6-7 liters) -equal to VC + RV
Digestion that occurs in the mouth is _____ compared to digestion that occurs in the stomach and small intestine
minimal
Saliva assists with
mechanical digestion -->lubricates and moistens food making it easier to manipulate and chemical digestion --> has enzymes that start break down of starch and fats
synovium
membrane (layer of soft tissue) in joint that secretes lubricating fluid called synovial fluid
periostenum
membrane surrounding bones; fibrous sheath rich in blood vessels and nerve tissue -->surrounds the long bone to protect it as well as serve as a site for muscle attachment -some periosteal cells are capable of differentiating into bone-forming cells -therefore a healthy periosteum is necessary for bone growth and repair
Mesoderm
middle layer produces: -musculoskeletal system -circulatory system (all the blood) -excretory system -gonads -muscular and connective tissue layers of digestive and respiratory system -adrenal cortex ** think Moveoderm because it develops into all the things that let you move around -how blood moves around body -muscles and bones let your body move -gonads let you "get around" ;)
M-line
middle of sarcomere -runs through the middle of the myosin fibers
The nerve terminal can also be called ______ when its synapsing with myocytes
motor end plate
reabsorption function of kidney
movement of solutes from filtrate to blood
adductor muscle
moves a part of the body toward the midline ex: pectoralis major
mucous cells secrete
mucus -->the mucus is bicarbonate rich and protects the muscular wall from the harshly acidic and proteolytic environment
A muscle is made up of parallel
muscle fibers
swallowing is initiated by
muscles of the oropharynx --->which constitute the upper esophageal sphincter
each ____ contains many myofibrils arranged in parallel and can also be called a ______
myocyte muscle fiber
frameshift mutation
mutation that shifts the "reading" frame of the genetic message by inserting or deleting nucleotides usually results in either complete change in the amino acid sequence after the insertion or deletion -->or premature truncation of the protein due to a stop codon being created early (nonsense mutation) types of frameshift mutations: -insertions -deletions
thick filaments are made of?
myosin
vibrissae
nasal hairs or whiskers -->filters air in humans
The functional unit of the kidney
nephron
How does aldosterone effect blood osmolarity?
no effect -bc causes increase in Na+ reabsorption and water follows so no net change
RBCs have no ______
nuclei or organelles --->means they can not divide -->makes more space for hemoglobin -->also bc there is no mitochondria means that the RBC won't use up any of the oxygen its carrying in aerobic respiration
Translocation mutation (chromosomal)
occur when a segment of DNA is swapped with a segment of DNA from another chromosome
In most cases, blood passes through _______ capillary bed before returning to the heart
one Three exceptions: -Hepatic portal system -Hypophyseal portal system -Renal portal system
Deletion mutation (chromosomal)
occurs when a large segment of DNA is lost from a chromosome
duplication mutation
occurs when a segement of DNA is copied many times in the genome (chromosomal mutation)
insertion mutation (chromosomal)
occurs when a segment of DNA is moved from one chromosome to another
hemizygous genotype
only one allele is present for that given gene ex: X chromosomes for males
organic vs inorganic components of bone
organic: collagen, glycoproteins, and other peptides inorganic: calcium, phosphate, hydroxide ions together form hydroxyapatite crystals (Ca10(PO4)6(OH)2) minerals such as magnesium, sodium, and potassium are also stored in bone
Which end of the muscle is the origin and which is the insertion?
origin= end of the muscle with the larger attachment to bone **usually the proximal connection insertion= end of the muscle with the smaller attachment to bone **usually the distal connection
bony matrix is ordered into structural units known as
osteons or Haversiam systems
papillary layer
outer layer of the dermis, directly beneath the epidermis Contains: -lose connective tissue
Ectoderm
outermost germ layer; produce: -integument (epidermis, hair, nails) -epithelia of the nose, mouth, and lower anal canal -lens of eye -nervous system (includes adrenal medulla) -inner ear ** think attracto derm bc makes up things that make us attractive to others like our hair and nose and lips --> also lets us tell if others are attractive using our eyes and ears and nervous system (brain)
stratum corneum
outermost layer of epidermis -contains several layers of dead, flattened keritinocytes -forms a barrier that prevents the invasion by pathogens and that helps prevent loss of fluids and salts
oxygen saturation definition and levels
oxygen saturation= the percentage of hemoglobin molecules carrying oxygen In lungs: 100% saturated In tissues: at rest--> 80% saturated (20% released) exercising--> 30% saturated (70% released)
What are the two equations of Hardy-Weinburg equilibrium?
p + q = 1 p^2 + 2pq + q^2 = 1 p = frequency of dominant allele (G) q = frequency of recessive allele (g) p^2 = frequency of GG 2pq = frequency of Gg q^2 = frequency of gg
Secretin
peptide hormone: -stimulates the pancreas to release bicarbonate to neutralize acid in duodenum. -reduces HCI secretion form parietal cells -causes pancreatic enzymes to be released into the duodenum -also slows movement of food thro the digestive tract to increase digestion time (an enterogastrone) **secreted by the duodenum
Three types of hormones based on chemical identity
peptide hormones, steroid, and amino acid derivative
Which type of B-cells produce antibodies
plasma cells >>>memory B-cells do not produce antibodies
membrane that surrounds the lungs
pleurae -the one on the surface of the lungs is the visceral pleura -the outer one is the parietal pleura
Bc gene pools change over time _______ evolve, ______ don't
populations evolve, individuals don't
what type of feedback is the binding and unbinding of oxygen from hemoglobin?
positive feedback --> spiraling forward -As one binds it becomes easier for more and more O2 to bind and the same for when one is released
intramembranous ossification
process by which bone forms directly from mesenchymal tissue (undifferentiated embryonic connective tissue) -->this occurs in the bones of the skull
endochondral ossification
process in which bone forms by replacing hyaline cartilage -occurs in the long bones of the body
transformation
process in which one strain of bacteria is changed by a gene or genes from another strain of bacteria -foreign genetic material usually comes from another bacteria that lysed and spilled their contents near a living bacteria -if this bacteria is capable of transformation it will take up this genetic material of the lysed bacteria and incorporate it -gram-negative rod bacteria can preform transformation
Apoptosis
programmed cell death -occurs through out development ex: webbing between fingers goes away -during apoptosis cell divides into self contained apoptotic blebs which are then broken down into apoptotic bodies and then digested by other cells -because its contained by a membrane it prevents the release of harmful substances into the environment
when do tetrads form during meiosis/mitosis?
prophase I of meiosis -->when homologous chromosomes pair up
albumin
protein in blood that maintains the proper oncotic pressure and also serves as a carrier for any drugs and hormones **made by liver
What are the two pumps in the heart
pulmonary--> right ventricle pumps blood to lungs systemic--> left ventricle pumps blood to body
What is reabsorbed and or secreted in the proximal convoluted tuble
reabsorbed (leave it): AAs, glucose, water-soluble vitamins, and majority of salts (70%!) secreted (enter it): H+, Urea, NH3, urea -->filtrate remains isotonic bc water and solutes leave solutes that leave enter the interstitium and are picked up by the vasa recta
What is reabsorbed and or secreted in the descending loop of henle
reabsorbed (leaves it): water --> as it gets deeper into the medulla of the kidney the osmolarity increases which forces out more water --> this water is picked up by the vasa recta -->but if don't want to conserve water then its osmolarity can be made to be isotonic with blood so water is retained in the urine --> or can be made to have 4x as high osmolarity to pull out more water when dehydrated
slow twitch muscle fibers
red muscle fibers that are fatigue resistant but have a slow contraction speed and a lower capacity for tension; usually recruited for endurance activities -also called type I muscle -have high myoglobin content -derive arg aerobically -contain many mitochondria to carry our oxidative phosphorylation ex: the muscles we use for posture
H-zone
region containing thick filaments only
I-band
region containing thin filaments only
Primary function of the kidneys
regulate blood volume and osmolarity does so thro: filtration, excretion and reabsorption
micturition reflex
relaxation of the internal urethral sphincter after parasympathetic activity has caused contraction of the detrusor muscle
Contracted detrusor muscle causes
relaxed internal urethral sphincter -->urine leaves bladder and waits till external urethral sphincter relaxes
Ovulation is the
release of egg/s from the ovaries. In humans, this event occurs when the ovarian follicles rupture and release the secondary oocyte ovarian cells.[1] After ovulation, during the luteal phase, the egg will be available to be fertilized by sperm. In addition, the uterine lining (endometrium) is thickened to be able to receive a fertilized egg. If no conception occurs, the uterine lining as well as blood will be shed during menstruation. -Humans release only one egg per month around the 14 day mark of the menstrual cycle -In the case of dizygotic twin there are two eggs released and fertilized
List the vessels in the renal vascular pathway, starting from the renal artery and ending at the renal vein.
renal artery -> afferent arteriole -> glomerulus -> efferent arteriole -> vasa recta -> renal vein
All the nephrons empty into the
renal pelvis which narrows to form the ureter
How is aldosterone regulated?
renin-angiotensin-aldosterone system 1) The juxtaglomerular cells of the kidney sense decreased blood pressure -->secrete renin 2) Renin cleaves the inactive plasma protein angiotensin into angiotensin I 3)In the lungs angiotensin I is converted into angiotensin II by ACE(angiotensin converting enzyme) 4a) Angiotensin II causes vasoconstriction and increased heart rate which helps increase blood pressure 4b)Angiotensin II also acts on the adrenal cortex, causing it to secrete aldosterone 5) Aldosterone acts on the nephrons, causing them to absorb more Na+ which results in H20 also being absorbed. 6) The result is an increased blood plasma volume which causes an increased cardiac output which causes an increase in blood pressure >>>Negative feedback: The increased blood pressure causes the juxtaglomular cells to stop secreting renin which stops the whole cycle
postzygotic isolation
reproductive isolation that allows for gamete fusion but yields either nonviable or sterile offspring ex: -hybrid inviability (formation of a zygote that can not develop to term) -hybrid sterility (form a hybrid that can not reproduce) -hybrid breakdown (form a hybrid that can reproduce but its offspring are inviable or infertile)
obligate aerobic bacteria
require oxygen to live
What is the binding of ATP required for in the actin-myosin cross-bridge cycle
required for releasing the myosin head from the actin filament
free nerve endings
respond to pain and temperature (located in dermis)
Anatomy of the respiratory system
right lung has three lobes left has two and has an indent for heart
Blood's path to lungs
right ventricle (deoxygenated blood) leaves --> pulmonary artery --> capillaries entering alveoli (pulmonary arteriole) **gas exchange** Oxygenated blood leaves thro capillary (pulmonary venue)--> joins up with pulmonary vein --> enters left atrium of the heart
lateral rotator
rotates the axis of the limb away from the midline ex: infraspinatus
medial rotator
rotates the axis of the limb toward the midline ex: subscapularis
The basic contractile unit of muscle
sarcomere
sarcomere --->muscle (structures from small to large)
sarcomere lined up end to end make a myofibril -myofibrils wrapped together in parallel by the sarcolemma forms a myocyte or muscle fiber -muscle fibers or myocytes in parallel form a muscle
Modes of natural selection
stabilizing selection, directional selection, disruptive selection
Cirrhosis
scarring of the liver leads to: -increased resistance in the hepatic portal vein that can cause a back up of fluid in portal system -this can then cause swollen veins in the digestive system -can also cause bleeding disorders bc production of clotting factor is disrupted -also leads to inability to properly dispose of ammonia which affects mentation (mental activity) -finally it can cause hepatocellular carcinoma
G-cells
secrete gastrin: A peptide hormone that induces the parietal cells in the stomach to secrete more HCl and signals the stomach to contract, mixing its contents -make up the pyloric glands
Mineralcorticoids (aldosterone)
secreted by: adrenal cortex ex: aldosterone (one tested on MCAT) -Target: kidneys -Effect: stimulates reabsorption of sodium in the distal convoluted tubule and the collection duct of the nephron (kidneys) -since water follows the salt the plasma osmolarity remains unchanged (unlike w/ ADH-only H20 absorbed-decreases osmolarity) -overall effect: increases blood pressure and blood volume -it also decreases the reabsorption of K+ and H+ in same areas of nephron ->promotes their excretion Controlled by: renin-angiotensin-aldosterone system
Glucocorticoids
secreted by: adrenal cortex -ex: cortisol and cortisone they cause: i)increased blood glucose levels -increase gluconeogenesis -decrease protein synthesis ii)decreased inflammation iii)decreased immunological response What causes their release? -ACTH released by anterior pituitary -ACTH is made in response to CRF made in hypothalamus **cortisol = stress hormone
how does the thyroid regulate calcium levels
secretes calcitonin -made in the c-cells -decreases calcium levels in three ways: i)increases calcium excretion from the kidneys ii) Decreases calcium absorption in the gut iii) Increases storage of calcium in the bone >>high levels of calcium in the blood cause secretion of calcitonin from the c-cells
pancreas endocrine
secretes insulin and glucagon and somatostatin -Its endocrine function is preformed by a group of cells called the islets of Langerhans (3 types): i)alpha: produce glucagon-> triggers glyconeogenesis to increase blood glucose levels ii)beta: produce insulin--> causes muscle and liver cells to take up glucose and store it as glycogen. iii)delta: produce somatostatin -->inhibits both insulin and glucagon secretion **Its exocrine function is the secretion of digestive enzymes
autolysis
self-destruction of cells; decomposition of all tissues by enzymes of their own formation without microbial assistance -occurs when lysosomes release their enzymes
merkel cells
sensory cells responsible for deep pressure and texture sensation with in the skin --> located at epidermal-dermal jxn
Meiosis II
sister chromatids separate -Similar to mitosis bc maintains the ploidy -but for meiosis it is the haploid or n that its maintaining whereas with mitosis it was diploid
chiasma
site of crossing over
Lacunae
small cavities in bone that contain osteocytes --> interconnected by tiny channels called canaliculi
Plasmids
small circular DNA molecules that replicate separately from the bacterial chromosome -therefore they are not considered part of the bacterial genome -genes may confer an advantage in antibiotic resistance -or additional virulence factors such as increased pathogenicity -subset of plasmids = episomes: plasmids that are capable of integrating into the genome of the bacterium
Which muscle types have myogenic activity?
smooth and cardiac -->This means that they will respond to nervous input, but do not require external signals to undergo contraction
Humoral Immunity
specific immunity produced by B cells that produce antibodies that circulate in body fluids -may take a week post initial infection to become fully effective
components of semen
sperm and seminal fluid
Blood pressure is measured with a
sphygmomanometer -->measures the gauge pressure in systemic circulation, which is the pressure above atmospheric pressure (760 mmHg at sea level)
Where does digestion start and end (generally)?
starts in mouth --> salivary amylase ends in small intestine
Epidermis layers (strata)
stratum corneum stratum lucidum stratum granulosum stratum spinosum stratum basale
Ruffini endings
stretch receptors (located in dermis)
what tells parasympathetic nervous system to make the detrusor muscle contract
stretch receptors in the bladder
Cardiac muscle is striated or unstriated?
striated
nonsense mutation
subsitution of wrong nucleotide into DNA that produces an early stop codon -->shortened protein usually results
circulatory pathway
superior and inferior vena cava-->right atrium->right ventricle--> pulmonary arteries--> lungs-->pulmonary veins-->left atrium--> left ventricle-->aorta--> body
trabeculae
supporting bundles of bony fibers in cancellous (spongy) bone -->area between them is filled with bone marrow
What does dermis contain
sweat glands, hair follicles, and blood vessels -->also most sensory receptors (ex: merkel cells, free nerve endings, meissner's corpsucles, and ruffini endings)
All of the glands except for the ______ gland are governed by the ______ nervous system
sweat, parasympathetic -->sweat gland is the only gland controlled by the sympathetic nervous system
Systole vs diastole
systole (contraction) and diastole (relaxation) **remember this bc if you are on a severe diet your heart rate will slow and you will be more relaxed bc you'll have less energy -->or that when you have a Seizure then there is lost of contraction -->or that asystole means a flat line which is when you have no contraction (systole)
label the bones of the foot
tarsals metatarsals phalanges
attach muscle to bone
tendons
Hemoglobin count
test used to measure hemoglobin content in a blood sample -->given as grams per deciliter normal numbers: Male = 13.5-17.5 Female = 12-16
oxygen debt
the amount of oxygen required after physical exercise to convert accumulated lactic acid to glucose -->also can be thought of as the difference between the amount of oxygen needed by cells versus the amount of oxygen actually present
Test cross (also called back cross)
the crossing of an individual of unknown genotype with a homozygous recessive individual to determine the unknown genotype -If offspring are 100% the dominant phenotype then the unknown genotype is likely homozygous dominant -If the offspring are 50% dominant then the unknown genotype is probably heterozygous -If no dominant then the unknown is likely homozygous recessive
stratum basale
the deepest layer of the epidermis -contains the stem cells that make the keratinocytes -melanocytes also found here
molecular clock model
the degree of difference in the genome between two species is related to the amount of time since the two species broke off from a common ancestor -->method molecular evolutionists use to estimate how long ago two species split off from a common ancestor
sympathetic nervous system
the division of the autonomic nervous system that arouses the body, mobilizing its energy in stressful situations Causes: -inhibits release of saliva -stimulates sweating and piloerection (hairs stand up) -increased HR -redistributes blood to muscles for locomotion -increases blood glucose -relaxes brooch -decreases digestion and peristalsis -dialates eyes to maximize light intake -releases epinephrine (adrenaline) in to blood stream -stimulates orgasm **The NT released by preganglioinic neurons is acetylcholine while the postganglionic neurons release norepinephrine.
parasympathetic nervous system
the division of the autonomic nervous system that calms the body, conserving its energy causes: -slower heart rate -constricts the bronchi -increases digestion by increasing peristalsis and increasing exocrine secretions -constricts pupils -stimulates flow of saliva -stimulates bile release -contracts bladder **Achetylcholine is the NT responsible for parasympathetic responses in the body -released by both pre and post ganglionic neurons
genetic leakage
the flow of genes between species (often forming hybrid offspring)
T3 and T4 produced by
the follicular cells of the thyroid -->tyrosine with iodine added (represented by the number following the T-->T 3 has three iodines)
Why are proteins or blood cells in the urine an indication that the filtration function of the kidney is having issues
the glomerulus has small pores so only small molecules such as glucose and glucose can pass into the blood that goes through the nephron -->proteins and cells are supposed to stay out of the filtrate and thus out of the urine
Pharynx
the membrane-lined cavity behind the nose and mouth, connecting them to the esophagus. -->it lets food and air pass through where as the larynx is only for air
cell differentiation
the process by which a cell becomes specialized for a specific structure or function. -done by selective transcription which is when a cell only has certain genes turned on -this is often carried out by induction >induction: the ability of one group of cells to influence the fate of nearby cells -inducers are chemicals that diffuse from the organizing cells and tell the responsive cells what genes to turn on -this is the process used to guide neuronal axons -also ensure that different cell types work together in an organ
outbreeding
the process of mating less closely related individuals when compared to the average of the population -->results in increased variation in a gene pool and increased fitness in a population
hematopoiesis
the production of blood cells and platelets -All starts in the bone marrow with hematopoietic stem cell
Penetrance
the proportion of individuals in the population carrying the allele who actually express the phenotype ->So its the probability that given a particular genotype, a person will express the phenotype ex: huntingtons -people with more than 40 sequence repeats (genotype) have full penetrance -->100 percent of individuals with this allele show symptoms -people with few sequence repeats can have low or even nonpenetrance -->low percent shows symptoms or in some alleles no one shows symptoms
simple twitch
the response of a single muscle fiber to a brief stimulus at or above the threshold stimulus and consists of a latent period, a contraction period, and a relaxation period
Y chromosome
the sex chromosome found only in males. When paired with an X chromosome from the mother, it produces a male child. -contains far less genetic information -but has the SRY or sex-determining-region which codes for a transcription factor that initiates testis differentiation and thus the formation of male gonads
Endocrine system
the system of glands that secrete hormones into the blood stream -The hormones are signaling molecules that act on distant tissues
latent period
the time between reaching threshold and the onset of contraction -->during this time that the action potential spreads along the muscle and allows calcium to be released by the SR
What is the nerve used to slow the heart rate
the vagus nerve -->under parasympathetic control
The lungs are contained in the ______ cavity
thoracic cavity -also contains the heart
A child that is seen to have a chromosome that has trisomy (three copies of some segments of DNA) and also has monosomy (only one copy of some segments of DNA) for another chromosome would indicate which type of mutation
translocation
Three types of bacterial genetic recombination events
transformation, conjugation, and transduction
Volkmann's canals
transverse channel (axis is perpendicular to bone) contains BVs, nerve fibers, and lymph vessels
Cells entering G2 have ____ as much DNA as cells in G1
twice
extracellular digestion
type of digestion in which food is broken down outside the cells in a digestive system and then absorbed -->technically occurs outside the body because the lumen of the GI tract connects to outside world
Intracellular digestion
type of digestion in which food is digested inside specialized cells that pass nutrients to other cells by diffusion
Thyroid hormones are made from
tyrosine modified by the addition of several iodines ** example of amino acid hormones bc of this structure
expressivity
varying phenotypes despite identical genotypes >classified as either variable or constant ex: A diseases has has the same mutation in the gene for every person but some people have debilitating tumors and some have cataracts and some have spinal lesions whereas some have no symptoms or effects -->so the disease has variable expressivity because the presentations range from no clinical effect to severe disability
Genes that never experience cross over that are very tightly linked have what recombination frequency?
very very close to 0%
virions
viral progeny
Larynx
voice box; passageway for air moving from pharynx to trachea; contains vocal cords --> covered by the epiglottis to keep food out
In order to be secreted into the urine a substance must be _______
water soluble >If a substance is not water soluble then it is either stored in the body, converted into water soluble products, or eliminated in the feces
inbreeding depression
when individuals with similar genotypes - typically relatives - breed with each other and produce offspring that have an impaired ability to survive and reproduce -->increases the level of homozygosity and decreases the heterozygosity which causes reduced fitness of population
fast twitch muscle fibers
white muscle fibers that contract rapidly and forcefully but fatigue quickly; usually recruited for actions requiring strength, power, or speed -called type II muscle -have lower amount of myoglobin -lower amount of mitochondria -ex: breast mucscle of birds that undergo short Burts of flight
sphincters of the anus
~ External - somatic (voluntary) ~ Internal - autonomic (involuntary)
Equation for the pressure differential across circulation
ΔP = CO x TPR ΔP - pressure differential across circulation CO - cardiac output TPR- total peripheral (vascular) resistance ** similar to V = IR equation**
