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Step 1 Buzzwords Physiology
USMLE Step 1 Recall: Buzzwords for the Boards Second Edition
Terms in this set (199)
In a ventricular pacemaker cell, what phase of the action potential is affected by NE?
Phase 4; NE increase the slope of the prepotential, allowing threshold to be reached sooner, and increases the rate of firing.
What is the effect of LH on the production of adrenal androgens?
LH has no effect on the production of adrenal androgens; ACTH stimulates adrenal androgen production.
What four conditions result in secondary hyperaldosteronism?
2. Vena caval obstruction or constriction
3. Hepatic cirrhosis
4. Renal artery stenosis
What are the five hormones produced by Sertoli cells?
2. Estradiol (E2)
3. Androgen-binding protein
4. Meiosis inhibiting factor (in fetal tissue)
5. Antimullerian hormone
Does the left or right vagus nerve innervate the SA node?
Right vagus innervates the SA node and the Left vagus innervates teh AV node.
What two factors result in the apex of the lung being hypoperfused?
Decreased pulmonary arterial pressure (low perfusion) and less-distensible vessels (high resistance) result in decreased blood flow at the apex.
What is the ratio of pulmonary to systemic blood flow?
1:!. Remember, the flow through the pulmonary circuit and the systemic circuit are equal.
To differentiate central from nephrogenic diabetes insipidus, after an injection of ADH, which will show a decreased urine flow?
Central. Remember, there is a deficiency in ADH production in the central form.
What wave is the cause of the following venous pulse deflections?
The rise in right atrial pressure secondary to blood filling and terminating when the tricuspid valves opens
What wave is the cause of the following venous pulse deflections? The bulging of the tricuspid valve into the right atrium
What wave is the cause of the following venous pulse deflections? The contraction of the right atrium
When a person goes from supine to standing, what happens to the following?
Dependent venous pressure
When a person goes from supine to standing, what happens to the following? Dependent venous blood volume
When a person goes from supine to standing, what happens to the following? Cardiac output
When a person goes from supine to standing, what happens to the following? BP
Remember, the carotid sinus reflex attempts to compensate by increasing both TPR and heart rate.
When does the hydrostatic pressure in Bowman's capsule play a role in opposing filtration?
It normally does not play a role in filtration but becomes important when there is an obstruction downstream.
What happens to intrapleural pressure when the diaphragam is contracted during inspiration?
Intrapleural pressure decreases (becomes more negative).
What is used as an index of cortisol secretion?
Urinary 17-OH steroids
What is the term that refers to the number of channels open in a cell membrane?
Membrane conductance (think conductance = channels open)
What are the five tissues in which glucose uptake is insulin independent?
2. Renal tubules
3. β Islet cells of the pancreas
5. GI mucosa
Place in order from fastest to slowest the rate of gastric emptying for CHO, fat, liquids, and proteins.
Liquids, CHO, protein, fat
Is most of the coronary artery blood flow during systole or diastole?
Diastole. During systole the left ventricle contracts, resulting in intramyocardial vessel compression and therefore very little blood flow in the coronary circulation.
What modified smooth muscle cell of the kidney monitor BP in the afferent arteriole?
The JG cells
What are the three functions of surfactant?
1. so it decreases recoil and increases compliance
3. Decrease probability of pulmonary edema formation (Reduces capillary filtration)
2. Promotes stability in small alveoli by lowering surface tension
What type of muscle is characterized by no myoglobin, anaerobic glycolysis, high ATPase activity, and large muscle mass?
White muscle, short term too
What is the most potent male sex hormone?
With a decrease in arterial diastolic pressure, what happens to
With a decrease in arterial diastolic pressure, what happens to TPR?
With a decrease in arterial diastolic pressure, what happens to Heart rate?
What linkage of complex CHOs does pancreatic amylase hydrolyze? What three complexes are formed?
Amylase hydrolyzes α-1,4-glucoside linkages, forming α-limit dextrins, maltotriose, and maltose.
Does the heart rate determine the diastolic or systolic interval?
Heart rate determines the diastolic interval, and contractility determines the systolic interval.
On a graphical representation of filtration, reabsorption, and excretion, when does glucose first appear in the urine?
At the beginning of splay is when the renal threshold for glucose occurs and the excess begins to spill over into the urine.
What is the relationship between preload and the passive tension in a muscle?
They are directly related; the greater the preload, the greater the passive tension in the muscle and the greater the prestretch of a sarcomere.
What is the rate-limiting step in the synthetic pathway of NE at the adrenergic nerve terminal?
The conversion of tyrosine to dopamine in the cytoplasm
How are flow through the loop of Henle and concentration of urine related?
As flow increases, the urine becomes more dilute because of decreased time for H2O reabsorption.
What is the PO2 of aortic blood in fetal circulation?
How do elevated blood glucose levels decrease GH secretion? (Hint: what inhibitory hypothalamic hormone is stimulated by IGF-1?)
Somatotrophins are stimulated by IGF-1, and they inhibit GH secretion. GHRH stimulates GH secretion.
What segment of the nephron has the highest concentration of inulin? Lowest concentration of inulin?
Terminal collecting duct has the highest concentration and Bowman's capsule has the lowest concentration of inulin.
What type of resistance system, high or low, is formed when resistors are added in a series?
A high-resistance systems is formed when resistors are added in a series.
What hormones, secreted in proportion to the size of the placenta, are an index of fetal well-being?
hCS and serum estriol, which are produced by the fetal liver and placenta, respectively, are used as estimates of fetal well-being.
What respiratory center in the caudal pons is the center for rhythm promoting prolonged inspirations?
Apneustic center (deep breathing place)
What area of the GI tract has the highest activity of brush border enzymes?
What is the term to describe the increased rate of secretion of adrenal androgens at the onset of puberty?
Does T3 or T4 have a greater affinity for its nuclear receptor?
T3 has a greater affinity for the nuclear receptor and therefore is considered the active form.
What is the amount in liters and percent body weight for the following compartments?
14 L, 33% of body weight
What is the amount in liters and percent body weight for the following compartments? Interstitial fluid
9.3 L, 15% of body weight
What is the amount in liters and percent body weight for the following compartments? ICF
28 L, 40% of body weight
What is the amount in liters and percent body weight for the following compartments? Vascular fluid
4.7 L, 5% of body weight
What is the amount in liters and percent body weight for the following compartments? Total body water
42 L, 67% of body weight
What hormone is secreted by the placenta late in pregnancy, stimulates mammary growth during pregnancy, mobilizes energy stores from the mother so that the fetus can use them, and has an amino acid sequence like GH?
Human chorionic somatomammotropin (hCS) or human placental lactogen (hPL)
What thyroid abnormality has the following? TRH increased, TSH decreased, T4 decreased
Secondary hypothyroidism/pituitary (Low TSH results in low T4 and increased TRH because of lack of a negative feedback loop.)
What thyroid abnormality has the following? TRH decreased, TSH decreased, T4 decreased
Tertiatry hypothydroidism/hypothalamic (Low TRH causes all the rest to be decreased because of decreased stimulation.)
What thyroid abnormality has the following? TRH increased, TSH increased, T4 decreased
Primary hypothyroidism (Low T4 has a decreased negative feedback loop, resulting in both the hypothalamus and the anterior pituitary gland to increase TRH and TSH release, respectively.)
What two stress hormones are under the permissive action of cortisol?
Glucagon and epinephrine
What prevents the down-regulation of the receptors on the gonadotrophs of the anterior pituitary gland?
The pulsatile release of GnRH
True or false? Epinaphrine has proteaolytic metabolic effects.
False. It has glycogenolytic and lipolytic actions but not proteolytic.
What is the only 17-hydroxysteroid with hormonal activity?
Cortisol, a 21-carbon steroid, has a -OH group at position 17.
Does the oncotic pressure of plasma promote filtration or reabsorption?
The oncotic pressure of plasma promotes reabsorption and is directly proportional to the filtration fraction.
Why is the base of the lung hyperventilated when a person is standing upright?
The alveoli at the base are small and very compliant, so there is a large change in their size and volume and therefore a high level of alveolar ventilation.
Be removing Na+ from the renal tubule and pumping it back into the ECF compartment, what does aldosterone do to the body's acid-base stores?
The removal of Na+ results in the renal tubule becoming negatively charged. The negative luminal charge attracks both K+ and H+ into the renal tubule and promotes HCO3- to enter the ECF and results in hypokalemic alkalosis.
What hormone causes contractions of smooth muscle, regulates interdigestive motility, and prepares the intestine for the next meal?
What is a sign of a Sertoli cell tumor in a man?
Excess estradiol in the blood
In the systemic circulation, what blood vessels have the largest pressure drop? Smallest pressure drop?
Arterioles have the largest drop, whereas the vena cava has the smallest pressure drop in systemic circulation.
What is the major stimulus for cell division in chondroblast?
What are two causes of diffusion impairment in the lungs?
Decrease in surface area and increase in membrane thickness (PalvO2 > PaO2)
What are the four effects of sucking on the mother?
1. Increased synthesis and secretion of oxytocin
2. Increased release of PIF by the hypothalamus
3. Inhibition of GnRH (suppressing FSH/LH)
4. Milk secretion
A migrating myoelectric complex is a propulsive movement of undigested material from the stomach to the small intestine to the colon. During a fast, what is the time interval of its repeats?
It repeats every 90 to 120 minutes and correlates with elevated levels of motilin.
With an increase in arterial systolic pressure, what happens to
With an increase in arterial systolic pressure, what happens to Vessel compliance?
With an increase in arterial systolic pressure, what happens to Heart rate?
In a ventricular pacemaker cell, what phase of the action potential is affected by ACh?
Phase 4; ACh hyperpolarizes the cell via increasing potassium conductance, taking longer to reach threshold and showing the rate of firing.
What form of renal tubular reabsorption is characterized by low back leaks, high affinity of a substance, and easy saturation? It is surmised that the entire filtered load is reabsorbed until the carriers are saturated, and then the rest is excreted.
A transport maximum (Tm) system
What is the term for the load on a muscle in the relaxed state?
Preload. It is the load on a muscle Prior to contraction.
What are the two best indices of left ventricular preload?
LVEDV and LVEDP (left ventricular end-diastolic volume and end-diastolic pressure, respectively)
What stage of male development is characterized by the following LH and testosterone levels? Both LH and testosterone levels drop and remain low.
What stage of male development is characterized by the following LH and testosterone levels? LH secretion drives testosterone production, with both levels paralleling each other.
Why is there an increase in prolactin if the hypothalamic-pituitary axis was severed?
Because the chronic inhibition of dopamine (PIF) on the release of prolactin from the anterior pituitary gland is removed, thereby increasing the secretion of prolactin.
What acid form of H+ in the urine cannot be titrated?
Regarding the venous system, what happens to blood volume if there is a small change in pressure?
Because the venous system is more compliant than the arterial vessels, small changes in pressure result in large changes in blood volume.
In what stage of sleep is GH secreted?
Stage 3 and 4 (NREM)
What two factors are required for effective exocytosis?
Calcium and ATP are required for packaged macromolecules to be extruded from the cell.
The opening of what valve indicates the termination of isovolumetric relaxation phase of the cardiac cycle?
Opening of the mitral valve indicates the termination of the isovolumetric relaxation phase and the beginning of the ventricular filling phase.
Why is there a decrease in the production in epinephrine when the anterior pituitary gland is removed?
The enzyme phenyl ethanolamine N-methylatransferase (PNMT), used in the conversion of epinephrine, is regulated by cortisol. Removing the anterior pituitary gland decreases ACTH and therefore cortisol.
How many carbons do estrogens have?
Estrogens are 18-carbon steroids. (Removal of one carbon from an androgen produces an estrogen.)
True or false? The alveolar PO2 and PCO2 levels match the pulmonary end capillary blood levels.
True. Because of intrapulmonary shunting, there is a slight decrease in PO2 and increase in PCO2 between the pulmonary end capillary blood and the systemic arterial blood.
In high altitudes, what is the main drive for ventilation?
The main drive shifts from central chemoreceptors (CSF H+) to peripheral chemoreceptors monitoring low PO2 levels.
True or false? Thyroid size is a measure of its function.
False. Thyroid size is a measure of TSH levels (which are giotrogenic).
What neurotransmitter is essential for maintaining a normal BP when an individual is standing?
NE, via its vasoconstriction action on blood vessels
Name the three methods of vasodilation via the sympathetic nervous system.
1. Decrease α1 activity
2. Increase β2 activity
3. Increase ACh levels
True or false? Cortisol inhibits glucose uptake in skeletal muscle.
True; cortisol inhibits glucose uptake in most tissue, making it available for neural tissue use.
Why would a puncture to a vein above the heart have the potential to introduce air into the vascular system?
Venous pressure above the heart is subatmospheric, so a puncture there has the potential to introduce air into the system.
What type of saliva is produced under parasympathetic stimulation?
High volume, watery solution; sympathetic stimulation results in thick, mucoid saliva.
In what area of the GI tract does iron get absorbed?
Why is the apex of the lung hypoventilated when a person is standing upright?
The alveoli at the apex are almost completely inflated prior to inflation, and although they are large, they receive low levels of alveolar ventilation.
What are the four characteristics of all protein-mediated transportation?
1. Competition for carrier with similar chemical substances
2. Chemical specificity needed for transportation
3. Zero-order saturation kinetics (Tranportation is maximal when all transporters are saturated.)
4. Rate of transportation faster than if by simple diffusion
Why is there an increase in FF if the GFR is decreased under sympathetic stimulation?
Because RPF is markedly decreased, while GFR is only minimally diminished; this results in an increase in FF (remember FF = GFR/RPF).
What triggers phase 3 of the action potential in a ventricular pacemaker cell?
Rapid efflux of potassium
What happens to the lung if the intrapleural pressure exceeds lung recoil?
The lung will expand; also the opposite is true.
What two factors determine the clearance of a substance?
Plasma concentration and excretion rate
What type of muscle contraction occurs when the muscle shortens and lifts the load placed on it?
What type of potential is characterized as being an all-or-none response, propagated and not summated?
What two pituitary hormones are produced by acidophils?
GH and prolactin are produced by acidophils; all others are by basophils.
What organ of the body has the smallest AV oxygen difference?
The renal circulation has the smallest AV O2 (high venous PO2) difference in the body because of the overperfusion of the kidneys resulting from filtration.
What is the titratable acid form of H+ in the urine?
H2PO4- (dihydrogen phosphate)
What hypothalamic hormone is synthesized in the preoptic nucleus?
What five factors promote turbulent flow?
1. Increased tube radius
2. Increased velocity
3. Decreased viscosity
4. Increased number of branches
5. Narrowing of an orifice
Where is most of the body's Ca2+ stored?
In bone; nearly 99% of Ca2+ is stored in the bone as hydroxyapatite.
What is the signal to open the voltage-gated transmembrane potassium channels?
Membrane depolarization is the stimulus to open these slow channels, and if they are prevented from opening, it will slow down the repolarization phase.
Increased urinary excretion of what substance is used to detect excess bone demineralization?
What is the ratio of T4:T3 secretion from the thyroid gland?
20:1 T4:T3. There is an increase in the production of T3 when iodine becomes deficient.
Do the PO2 peripheral chemoreceptors of the carotid body contribute to the normal drive for ventilation?
Under normal resting conditions NO, but they are strongly stimulated when PO2 arterial levels decrease to 50 to 60 mmHg, resulting in increased ventilatory drive.
What determines the overall force generated by the ventricular muscle during systole?
The number of cross-bridges cycling during contraction: the greater the number, the greater the force of contraction.
Where does most circulating plasma epinephrine originate?
From the adrenal medulla; NE is mainly derived from the postsynaptic sympathetic neurons.
What happens to intracellular volume when there is an increase in osmolarity?
ICF volume decreases when there is an increase in osmolarity and vice versa.
Which CHO is independently absorbed from the small intestine?
Fructose; both glucose and galactose are actively absorbed via secondary active transport.
When is the surface tension the greatest in the respiratory cycle?
Surface tension, the force to collapse the lung, is greatest at the end of inspiration.
In reference to membrane potential (Em) and equilibrium potential (Ex), which way do ions diffuse?
Ions diffuse in the direction to bring the membrane potential toward the equilibrium potential.
Under normal conditions, what is the main factor that determines GFR?
Hydrostatic pressure of the glomerular capillaries (promotes filtration)
The closure of what valve indicates the beginning of the isovolumetric relaxation phase of the cardiac cycle?
Closure of the aortic valve indicates the termination of the ejection phase and the beginning of the isovolumetric relaxation phase of the cardiac cycle.
What vessels in the systemic circulation have the greatest and slowest velocity?
The aorta has the greatest velocity and the capillaries have the slowest velocity.
What three lung measurements must be calculated because they cannot be measured by simple spirometry?
TLC, FRC, and RV have to be calculated. (Remember, any volume that has RV as a component has be calculated.)
What is the venous and arterial stretch receptors' function regarding the secretion of ADH?
They chronically inhibit ADH secretion; when there is a decrease in the blood volume, the stretch receptors send fewer signals, and ADH is secreted.
What cell converts androgens to estrogens?
What hormone acts on Granulosa cell?
How long is the transit time through the large intestine?
3 to 4 days
Does subatmospheric pressure act to expand or collapse the lung?
Subatmospheric pressure acts to expand the lung; positive pressure acts to collapse the lung.
Why is there a minimal change in BP during exercise if there is a large drop in TPR?
Because the large drop in TPR is accompanied by a large increase in cardiac output, resulting in a minimal change in BP.
What triggers phase 0 of the action potential in a ventricular pacemaker cell?
Calcium influx secondary to slow channel opening
What are the following changes seen in the luminal fluid by the time it leaves the PCT of the nephron?
Percentage of original filtered volume left in the lumen
At the end of the PCT 25% of the original volume is left
What are the following changes seen in the luminal fluid by the time it leaves the PCT of the nephron? Percentage of Na+, Cl-, K+ left in the lumen
At the end of the PCT 25% of Na+, Cl-, K+ is left
What are the following changes seen in the luminal fluid by the time it leaves the PCT of the nephron? Osmolarity
True or false? Enterokinase is a brush border enzyme.
False. It is an enzyme secreted by the lining of the small intestine.
What cells of the parathyroid gland are simulated in response to hypocalcemia?
The chief cells of the parathyroid gland release PTH in response to hypocalcemia.
At the base of the lung, what is the baseline intrapleural pressure, and what force does it exert on the alveoli?
Intrapleural pressure at the base is -2.5 cm H2O (more positive than the mean), resulting in a force to collapse the alveoli.
What hormone is necessary for normal GH secretion?
Normal thyroid hormones levels in the plasma are necessary for proper secretion of GH. Hypothyroid patients have decreased GH secretions.
What is the most energy-demanding phase of the cardiac cycle?
What presynaptic receptor does NE use to terminate further neurotransmitter release?
Are salivary secretions hypertonic, hypotonic, or isotonic?
Hypotonic, because NaCl is reabsorbed in the salivary ducts
Why will turbulence first appear in the aorta in patients with anemia?
Because it is the largest vessel and has the highest velocity in systemic circulation
What is the origin of the polyuria if a patient is dehydrated and electrolyte depleted?
If the polyuria begins before the collecting ducts, the patient is dehydrated and electrolyte depleted. If the polyuria originates from the collecting ducts, the patient is dehydrated with normal electrolytes.
What is the physiologically active form of Ca2+?
Free ionized Ca2+
What are the two factors that affect alveolar PCO2 levels?
Metabolic rate and alveolar ventilation (main factor)
What term is described as the prestretch on the ventricular muscle at the end of diastole?
Preload (the load on the muscle in the relaxed state)
What peripheral chemoreceptor receives the most blood per gram of weight in the body?
The carotid body, which monitors arterial blood directly
When do hCG concentrations peak in pregnancy?
In the first 3 months
How many milliliters of O2 per mililiter of blood?
What type of cell is surrounded by mineralized bone?
What two forces affect movement of ions across a membrane?
Concentration force and electrical force
How is velocity related to the total cross-sectional area of a blood vessel?
Velocity is inversely related to cross-sectional area.
True or false? Aldosterone has a sodium-conserving action in the distal colon.
True. In the distal colon, sweat glands, and salivary ducts, aldosterone has sodium-conserving effects.
What form of hormone is described as having membrane-bound receptors that are stored in vesicles, using second messengers, and having its activity determined by free hormone levels.
Water-soluble hormones are considered fast-acting hormones.
What disorder of aldosterone secretion is characterized by
Increased total body sodium, ECF volume, plasma volume, BP, and pH; decreased potassium, renin and AT II activity; no edema?
Primary hyperaldosteronism (Conn syndrome)
What disorder of aldosterone secretion is characterized by Decreased total body sodium, ECF volume, plasma volume, BP, and pH; increased potassium, renin, and AT II activity; no edema?
Primary hypoaldosteronism (Addison's disease)
What four factors affect diffusion rate?
1. Concentration (greater concentration gradient, greater diffusion rate)
2. Surface area (greater surface area, greater diffusion rate)
3. Solubility (greater solubility, greater diffusion rate)
4. Membrane thickness (thicker the membrane, slower the diffusion rate)
Molecular weight is clinically unimportant.
How long after ovulation does fertilization occur?
8 to 25 hours
What is the name of the force that develops in the wall of the lungs as they expand?
Lung recoil, being a force to collapse the lung, increases as the lung enlarges during inspiration.
How does sympathetic stimulation to the skin result in decreased blood flow and decreased blood volume? (Hint: what vessels are stimulated, and how?)
A decrease in cutaneous blood flow results from constriction of the arterioles, and decreased cutaneous blood volume results from constriction of the venous plexus.
What two compensatory mechanisms occur to reverse hypoxia at high altitudes?
Increase in erythropoietin and increase in 2,3-BPG, also called 2,3-diphosphoglycerate (2,3,-P2Gri) (increase in glycolysis)
What female follicular cell is under LH stimulation and produces androgens from cholesterol?
What is the main factor determing FF?
Renal plasma flow (decrease flow, increase FF)
Where is the action potential generated on a neuron?
What three factors increase simple diffusion?
1. Increased solubility
2. Increased concentration gradient
3. Decreased thickness of the membrane
What is the rate-limiting step in a conduction of a NMJ?
The time it takes ACh to diffuse to the postjunctional membrane
What growth factors are chondrogenic, working on the epiphyseal end plates of bone?
What determines the Vmax of skeletal muscle?
The muscle's ATPase activity
True or false? All of the hormones in the hypothalamus and anterior pituitary gland are water soluble.
What is the effect of T3 on the glucose absorption in the small intestine?
Thyroid hormones increase serum glucose levels by increasing the absorption of glucose from the small intestine.
Is the bound form or free form of a lipid-soluble hormone responsible for the negative feedback activity?
Free form determines hormone activity and is responsible for the negative feedback loop.
What region or regions of the adrenal cortex are stimulated by ACTH?
Zona fasciculata and zona reticularis
Are the following parameters associated with an obstructive or restrictive lung disorder; decreased FEV1, FVC, peak flow, and FEV1/FVC; increased TLC, FRC, and RV?
Obstructive lung disorders. The opposite changes (where you see decrease exchange it for increase and vice versa) are seen in a restrictive pattern.
During puberty, what is the main drive for the increased GH secretion?
Increased androgen secretion at puberty drives the increased GH secretion.
What type of potential is characterized as graded, decremental, and exhibiting summation?
What three organs are responsible for peripheral conversion of T4 to T3?
Liver, kidneys, and pituitary gland via 5' deiodinase enzyme
At the apex of the lung, what is the baseline intrapleural pressure, and what force does it exert on the alveoli?
Baseline apical intrapleural pressure is -10 cmH2o (more negative than the mean) resulting in a force to expand the alveoli.
True or false? Renin secretion is increased in 21-β-hydroxylase deficiency.
True. Increased renin and AT II levels occur as a result of the decreased production of aldosterone.
What are the four ways to increase TPR?
1. Decrease the radius of the vessel
2. Increase the length of the vessel
3. Increase the viscosity
4. Decrease the number of parallel channels
What form of estrogen is of placental origin?
What term is an index of the effort needed to expand the lungs (i.e., overcomes recoil)?
Compliance; the more compliant a lung is, the easier it is to inflate.
At which three sites in the body is T4 converted to T3?
3. Pituitary gland (via 5'-deiodinase enzyme)
Using Laplace's relationship regarding wall tension, why is the wall tension in a aneurysm greater than in the surrounding normal blood vessel's wall?
The wall tension is greater because the aneurysm has a greater radius than the surrounding vessel.
What percentage of nephrons is cortical?
Seven-eighths of nephrons are cortical, with the remainder juxtamedullary.
What is the major muscle used in the relaxed state of expiration?
Under resting conditions expiration is considered a passive process; therefore, no muscles are used. In the active state the abdominal muscles can be considered the major muscle of expiration.
What is it called when levels of sex steroids increase, LH increases, and FSH increases?
GnRH pulsatile infusion
What parasympathetic neurotransmitter of the GI tract stimulates the release of gastrin?
Gastrin-releasing peptide (GRP) stimulates G cells to release gastrin. (All G's)
What reflex increases TPR in an attempt to maintain BP during a hemorrhage?
The carotid sinus reflex
What is the main factor determining GFR?
Glomerular capillary pressure (increased glomerular capillary pressure, increased GFR and vice versa)
What is the effect of hypoventilation on cerebral blood flow?
Hypoventilation results in an increase in PCO2 levels and therefore an increase in blood flow.
What does failure of PaO2 to increase with supplemental O2 indicate?
Pulmonary shunt (i.e., pulmonary embolism)
What two substances stimulate Sertoli cells?
FSH and testosterone
The clearance of what substance is the gold standard of RPF?
What are the growth factors released from the liver called?
Regarding skeletal muscle mechanics, what is the relationship between velocity and afterload?
An increase in the afterload decreases velocity; they are inversely related. (V equals 1 divided by afterload.)
What are the six substances that promote the secretion of insulin?
2. Amino acid (arginine)
3. Gastrin inhibitory peptide (GIP)
Does O2 or CO2 have a higher driving force across the alveolar membrane?
O2 has a higher driving force but is only one-twenty-fourth as soluble as CO2. CO2 has a very small partial pressure difference across the alveolar membrane (47 - 40 = 7 mmHg), but it is extremely soluble and therefore diffuses readily across the membrane.
What is used as an index for both adrenal and testicular androgens?
What hormone, stimulated by epinephrine, results in an increase in lipolysis?
Hormone-sensitive lipase, which breaks down triglyceride into glycerol and free fatty acid
Is GH considered a gluconeogenic hormone?
Yes, it decreases fat and muscle uptake of glucose, thereby increasing blood glucose levels.
True or false? Somatic motor neutrons innervate the striated muscle of the bulbospongiosus and ischiocavernous muscles and result in ejaculation of semen.
What two factors lead to the development of the bends (caisson disease)?
Breathing high-pressure nitrogen over a long time and sudden decompression result in the bends.