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544 Cards in this Set

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In a ventricular pacemaker cell, what phase of the action potential is affected by NE?
Phase 4; NE increases the slope of the prepotential, allowing threshold to be reached sooner, and increases the rate of firing.
Anatomical and alveolar dead spaces together constitute what space?
Physiologic dead space is the total dead space of the respiratory system.
What three organs are necessary for the production of vitamin D3(cholecalciferol)?
Skin, liver, and kidneys
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?
1. CHF
2. Vena caval obstruction or constriction
3. Hepatic cirrhosis
4. Renal artery stenosis
What are the five hormones produced by Sertoli cells?
1. Inhibin
2. Estradiol (E2)
3. Androgen-binding protein
4. Meiosis inhibiting factor (in fetal tissue)
5. Antimüullerian hormone
What is the term for the negative resting membrane potential moving toward threshold?
Depolarization (i.e., Na+ influx)
Does the left or right vagus nerve innervate the SA node?
Right vagus innervates the SA node and the left vagus innervates the AV node
How does ventricular repolarization take place, base to apex or vice versa?
Repolarization is from base to apex and from epicardium to endocardium.
What is the term for any region of the respiratory system that is incapable of gas exchange?
Anatomical dead space, which ends at the level of the terminal bronchioles.
What four factors shift the Hgb-O2 dissociation curve to the right? What is the consequence of this shift?
Increased CO2, H+, temperature, and 2, 3-BPG levels all shift the curve to the right, thereby making the O2 easier to remove (decreased affinity) from the Hgb molecule.
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?
1:1. 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.
In what area of the GI tract are water-soluble vitamins absorbed?
Duodenum
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
V wave
What wave is the cause of the following venous pulse deflections?
• The bulging of the tricuspid valve into the right atrium
C wave
What wave is the cause of the following venous pulse deflections?
• The contraction of the right atrium
A wave
What are the four functions of saliva?
1. Provide antibacterial action
2. Lubricate
3. Begin CHO digestion
4. Begin fat digestion
When a person goes from supine to standing, what happens to the following?
• Dependent venous pressure
Increases

Remember, the carotid sinus reflex attempts to compensate by increasing both TPR and heart rate.


--------------------------------------------------------------------------------
When a person goes from supine to standing, what happens to the following?
• Dependent venous blood volume
Increases

Remember, the carotid sinus reflex attempts to compensate by increasing both TPR and heart rate.


--------------------------------------------------------------------------------
When a person goes from supine to standing, what happens to the following?
• Cardiac output
Decreases

Remember, the carotid sinus reflex attempts to compensate by increasing both TPR and heart rate.
When a person goes from supine to standing, what happens to the following?
• BP
Decreases

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 diaphragm is ontracted during inspiration?
Intrapleural pressure decreases (becomes more negative).
What is used as an index of cortisol secretion?
Urinary 17-OH steroids
If the pH is low with increased CO2 levels and decreased HCO3- levels, what is the acid-base disturbance?
Combined metabolic and respiratory acidosis
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?
1. CNS
2. Renal tubules
3. Beta Islet cells of the pancreas
4. RBCs
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 cells of the kidney monitor BP in the afferent arteriole?
The JG cells
What are the three functions of surfactant?
1. Increase compliance
2. Decrease surface tension
3. Decrease probability of pulmonary edema formation
Name the hormone—glucagon, insulin, or epinephrine:
• Glycogenolytic, gluconeogenic, lipolytic, glycolytic, and stimulated by hypoglycemia
Epinephrine
Name the hormone—glucagon, insulin, or epinephrine:
• Glycogenolytic, gluconeogenic, lipolytic, glycolytic, proteolytic, and stimulated by hypoglycemia and AAs
Glucagon
Name the hormone—glucagon, insulin, or epinephrine:
• Glycogenic, gluconeogenic, lipogenic, proteogenic, glycolytic, and stimulated by hyperglycemia, AAs, fatty acids, ketosis, ACh, GH, and Beta-agonist
Insulin
Is the hydrophobic or hydrophilic end of the phospholipids of the cell membrane facing the aqueous environment?
Hydrophilic (water-soluble) end faces the aqueous environment and the hydrophobic (water-insoluble) end faces the interior of the cell.
What type of muscle is characterized by no myoglobin, anaerobic glycolysis, high ATPase activity, and large muscle mass?
White muscle; short term too
What percentage of CO2 is carried in the plasma as HCO3- ?
90% as HCO3-, 5% as carbamino compounds, and 5% as dissolved CO2
What is the most potent male sex hormone?
Dihydrotestosterone
With a decrease in arterial diastolic pressure, what happens to
• Stroke volume?
Decreases
With a decrease in arterial diastolic pressure, what happens to
• TPR?
Decreases
With a decrease in arterial diastolic pressure, what happens to
• Heart rate?
Decreases
What linkage of complex CHOs does pancreatic amylase hydrolyze? What three complexes are formed?
Amylase hydrolyzes alpha-1, 4-glucoside linkages, forming alpha-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 many days prior to ovulation does LH surge occur in the menstrual cycle?
1 day prior to ovulation
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?
60%
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 system 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 primary acid-base disturbance is caused by an increase in alveolar ventilation (decreasing CO2 levels) resulting in the reaction shifting to the left and decreasing both H+ and HCO3- levels?
Respiratory alkalosis (summary: low CO2, low H+, slightly low HCO3-)
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?
Jejunum (upper)
What is the term to describe the increased rate of secretion of adrenal androgens at the onset of puberty?
Adrenarche
What period is described when a larger-than-normal stimulus is needed to produce an action potential?
Relative refractory period
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 are the three main functions of surfactant?
1. Lowers surface tension, so it decreases recoil and increases compliance
2. Reduces capillary filtration
3. Promotes stability in small alveoli by lowering surface tension
What is the only important physiological signal regulating the release of PTH?
Low interstitial free Ca2+ concentrations
What endocrine abnormality is characterized by the following changes in PTH, Ca2+, and inorganic phosphate (Pi)?
• PTH decreased, Ca2+ increased, Pi increased
Secondary hypoparathyroidism (vitamin D toxicity)
What endocrine abnormality is characterized by the following changes in PTH, Ca2+, and inorganic phosphate (Pi)?
• PTH increased, Ca2+ decreased, Pi decreased
Secondary hyperparathyroidism (vitamin D deficiency, renal disease)
What endocrine abnormality is characterized by the following changes in PTH, Ca2+, and inorganic phosphate (Pi)?
• PTH decreased, Ca2+ decreased, Pi increased
Primary hypoparathyroidism
What endocrine abnormality is characterized by the following changes in PTH, Ca2+, and inorganic phosphate (Pi)?
• PTH increased, Ca2+ increased, Pi decreased
Primary hyperparathyroidism
What is the amount in liters and percent body weight for the following compartments?
• ECF
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 decreased, TSH decreased, T4 increased
Graves disease (Increased T4 decreases TRH and TSH through negative feedback.)
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
Tertiary hypothyroidism/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 thyroid abnormality has the following?
• TRH decreased, TSH decreased, T4 increased
Secondary hyperthyroidism (Increased TSH results in increased T4 production and increased negative feedback on to hypothalamus and decreased release of TRH.)
What two stress hormones are under the permissive action of cortisol?
Glucagon and epinephrine
If the radius of a vessel doubles, what happens to resistance?
The resistance will decrease one-sixteenth of the original resistance.
What prevents the down-regulation of the receptors on the gonadotrophs of the anterior pituitary gland?
The pulsatile release of GnRH
True or false? Epinephrine has proteolytic 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.
By 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 attracts 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?
Motilin
What two vessels in fetal circulation have the highest PO2 levels?
Umbilical vein and ductus venosus (80%)
How many days prior to ovulation does estradiol peak in the menstrual cycle?
2 days prior to ovulation
What serves as a marker of endogenous insulin secretion?
C-peptide levels
What is the term for the total volume of air moved in and out of the respiratory system per minute?
Total ventilation (minute ventilation or minute volume)
What is the renal compensation mechanism for alkalosis?
Increase in urinary excretion of HCO3-, shifting the reaction to the right and increasing H+
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 chondroblasts?
IGF-1
What are two causes of diffusion impairment in the lungs?
Decrease in surface area and increase in membrane thickness (Palv O2 > PaO2)
What are the four effects of suckling 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 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
• Stroke volume?
Increases
With an increase in arterial systolic pressure, what happens to
• Vessel compliance?
Decreases
With an increase in arterial systolic pressure, what happens to
• Heart rate?
Decreases
What enzyme is needed to activate the following reactions?
• Trypsinogen to trypsin
Enterokinase
What enzyme is needed to activate the following reactions?
• Chymotrypsinogen to chymotrypsin
Trypsin
What enzyme is needed to activate the following reactions?
• Procarboxypeptidase to carboxypeptidase
Trypsin
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 slowing the rate of firing.
What is the most potent stimulus for glucagon secretion? Inhibition?
Hypoglycemia for secretion and hyperglycemia for inhibition
What is the term for the summation of mechanical stimuli due to the skeletal muscle contractile unit becoming saturated with calcium?
Tetany
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
In an adrenergic nerve terminal, where is dopamine converted to NE? By what enzyme?
Dopamine is converted into NE in the vesicle via the enzyme dopamine-Beta-hydroxylase.
Is the clearance for a substance greater than or less than for inulin if it is freely filtered and secreted? If it is freely filtered and reabsorbed?
Filtered and secreted: Cx > Cin (i.e., PAH). Filtered and reabsorbed: Cx < Cin (i.e., glucose), where Cx = clearance of a substance and Cin = clearance of inulin.
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.
The surge of what hormone induces ovulation?
LH
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?
• LH pulsatile amplitude and levels increase, with increased testosterone production.
Puberty
What stage of male development is characterized by the following LH and testosterone levels?
• Both LH and testosterone levels drop and remain low.
Childhood
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.
Adulthood
What stage of male development is characterized by the following LH and testosterone levels?
• Decreased testosterone production is accompanied by an increase in LH production.
Aged adult
What primary acid-base disturbance is caused by a loss in fixed acid forcing the reaction to shift to the right, thereby increasing HCO3- levels?
Metabolic alkalosis (summary: high pH, low H+ and high HCO3-)
When referring to a series circuit, what happens to resistance when a resistor is added?
Resistance increases as resistors are added to the circuit.
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.
Why is the clearance of creatinine always slightly greater than the clearance of inulin and GFR?
Because creatinine is filtered and a small amount is secreted
What acid form of H+ in the urine cannot be titrated?
NH4+(ammonium)
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?
Stages 3 and 4 (NREM)
Where does the conversion of CO2 into HCO3- take place?
In the RBC; remember, you need carbonic anhydrase for the conversion, and plasma does not have this enzyme.
From the fourth month of fetal life to term, what secretes the progesterone and estrogen to maintains the uterus?
The placenta
What two factors are required for effective exocytosis?
Calcium and ATP are required for packaged macromolecules to be extruded from the cell.
What is the best measure of total body vitamin D if you suspect a deficiency?
Serum 25-hydroxy-vitamin D (25-OH-D)
What hormone is required for 1, 25-dihydroxy-vitamin D (1, 25-diOH-D) to have bone resorbing effects?
PTH
Is bone deposition or resorption due to increased interstitial Ca2+concentrations?
Bone deposition increases with increased Ca2+ or PO 4- concentrations, whereas resorption (breakdown) is increased when there are low levels of Ca2+ or PO4-.
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-methyltransferase (PNMT), used in the conversion of epinephrine, is regulated by cortisol. Removing the anterior pituitary gland decreases ACTH and therefore cortisol.
Name the period described by the following statement: no matter how strong a stimulus is, no further action potentials can be stimulated.
Absolute refractory period is due to voltage inactivation of sodium channels.
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.
Describe what type of fluid is either gained or lost with the following changes in body hydration for the ECF volume, ICF volume, and body osmolarity, respectively:
• ECF, decrease; ICF, no change; body, no change
Loss of isotonic fluid (diarrhea, vomiting, hemorrhage)
Describe what type of fluid is either gained or lost with the following changes in body hydration for the ECF volume, ICF volume, and body osmolarity, respectively:
• ECF, increase; ICF, increase; body, decrease
Gain of hypotonic fluid (water intoxication or hypotonic saline)
Describe what type of fluid is either gained or lost with the following changes in body hydration for the ECF volume, ICF volume, and body osmolarity, respectively:
• ECF, decrease; ICF, decrease; body: increase
Loss of hypotonic fluid (alcohol, diabetes insipidus, dehydration)
Describe what type of fluid is either gained or lost with the following changes in body hydration for the ECF volume, ICF volume, and body osmolarity, respectively:
• ECF: increase; ICF: no change; body: no change
Gain of isotonic fluid (isotonic saline)
Describe what type of fluid is either gained or lost with the following changes in body hydration for the ECF volume, ICF volume, and body osmolarity, respectively:
• ECF, increase; ICF, decrease; body, increase
Gain of hypertonic fluid (mannitol or hypertonic saline)
What hormone excess produces adrenal hyperplasia?
ACTH
Is there more circulating T3 or T4 in plasma?
T4; because of the greater affinity for the binding protein, T4 has a significantly (nearly fifty times) longer half-life than T3.
Why is the cell's resting membrane potential negative?
The resting membrane potential of the cell is -90 mV because of the intracellular proteins.
True or false? Thyroid size is a measure of its function.
False. Thyroid size is a measure of TSH levels (which are goitrogenic).
If the radius of a vessel is decreased by half, what happens to the resistance?
The resistance increases 16-fold.
What neurotransmitter is essential for maintaining a normal BP when an individual is standing?
NE, via its vasoconstrictive action on blood vessels
What form of diabetes insipidus is due to an insufficient amount of ADH for the renal collecting ducts?
Central/neurogenic diabetes insipidus; in the nephrogenic form there is sufficient ADH available, but the renal collecting ducts are impermeable to its actions.
Name the three methods of vasodilation via the sympathetic nervous system.
1. Decrease alpha-1 activity
2. Increase Beta-2 activity
3. Increase ACh levels
What hormone is characterized by the following renal effects?
• Calcium reabsorption, phosphate excretion
PTH
What hormone is characterized by the following renal effects?
• Calcium excretion, phosphate excretion
Calcitriol
What hormone is characterized by the following renal effects?
• Calcium reabsorption, phosphate reabsorption
Vitamin D3
True or false? Progesterone has thermogenic activities.
True. Elevated plasma levels of progesterone can raise the body temperature 0.5° to 1.0°F.
How long is the transit time through the small intestine?
2 to 4 hours
Where is the last conducting zone of the lungs?
Terminal bronchioles. (No gas exchange occurs here.)
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.
What percentage of cardiac output flows through the pulmonary circuit?
100%; the percentage of blood flow through the pulmonary and systemic circulations are equal.
Name the Hgb-O2 binding site based on the following information:
• Least affinity for O2; requires the highest PO 2 levels for attachment (approx. 100 mm Hg)
Site 4
Name the Hgb-O2 binding site based on the following information:
• Greatest affinity of the three remaining sites for attachment; requires PO2 levels of 26 mm Hg to remain attached
Site 2
Name the Hgb-O2 binding site based on the following information:
• Remains attached under most physiologic conditions
Site 1
Name the Hgb-O2 binding site based on the following information:
• Requires a PO2 level of 40 mm Hg to remain attached
Site 3
Which three factors cause the release of epinephrine from the adrenal medulla?
1. Exercise
2. Emergencies (stress)
3. Exposure to cold


(The three Es)
How many ATPs are hydrolyzed every time a skeletal muscle cross-bridge completes a single cycle?
One, and it provides the energy for mechanical contraction.
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?
Duodenum
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 pancreatic islet cell secretes glucagons?
alpha-Cells; glucagon has stimulatory effects on -cells and inhibitory effects on -cells.
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 (Transportation is maximal when all transporters are saturated.)
4. Rate of transportation faster than if by simple diffusion
What is secretin's pancreatic action?
Secretin stimulates the pancreas to secrete a HCO3--rich solution to neutralize the acidity of the chyme entering the duodenum.
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 is the primary target for the action of glucagon?
Liver (hepatocytes)
What is the renal compensation mechanism for acidosis?
Production of HCO3-, shifting the reaction to the left and thereby decreasing H+
What enzyme found in a cholinergic synapse breaks down ACh? What are the byproducts?
Acetylcholinesterase breaks ACh into acetate and choline (which gets resorbed by the presynaptic nerve terminal).
What hormone, produced by Sertoli cells, if absent would result in the formation of internal female structures?
MIF
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?
Isotonic contraction
What type of potential is characterized as being an all-or-none response, propagated and not summated?
Action potential
What primary acid-base disturbance is caused by a gain in fixed acid forcing the reaction to shift to the left, decreasing HCO3- and slightly increasing CO2?
Metabolic acidosis (summary: low pH, high H+, and low HCO3-)
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?
GnRH
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
What is the major hormone produced in the following areas of the adrenal cortex?
• Zona glomerulosa
Aldosterone

Remember, from the outer cortex to the inner layer, Salt, Sugar, Sex. The adrenal cortex gets sweeter as you go deeper.
What is the major hormone produced in the following areas of the adrenal cortex?
• Zona fasciculata
Cortisol

Remember, from the outer cortex to the inner layer, Salt, Sugar, Sex. The adrenal cortex gets sweeter as you go deeper.
What is the major hormone produced in the following areas of the adrenal cortex?
• Zona reticularis
DHEA (androgens)

Remember, from the outer cortex to the inner layer, Salt, Sugar, Sex. The adrenal cortex gets sweeter as you go deeper.
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 relationship between ventilation and PCO2 levels?
They are inversely related. If ventilation increases, there will be a decrease in PCO2 levels and vice versa.
Is T3 or T4 responsible for the negative feedback loop on to the hypothalamus and anterior pituitary gland?
T4, as long as T4 levels remain constant, TSH will be minimally effected by T3.
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?
Hydroxyproline
What is the term to describe how easily a vessel stretches?
Compliance (think of it as distensibility)
What is the ratio of T4:T3 secretion from the thyroid gland?
20:1T4T3. 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 mm Hg, 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 causes a skeletal muscle contraction to terminate?
When calcium is removed from troponin and pumped back into the SR, skeletal muscle contraction stops.
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.
What adrenal enzyme deficiency results in hypertension, hypernatremia, increased ECF volume, and decreased adrenal androgen production?
17-alpha-Hydroxylase deficiency
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.
Thin extremities, fat collection on the upper back and abdomen, hypertension, hypokalemic alkalosis, acne, hirsutism, wide purple striae, osteoporosis, hyperlipidemia, hyperglycemia with insulin resistance, and protein depletion are all characteristics of what disorder?
Hypercortisolism (Cushing syndrome)
What enzyme is essential for the conversion of CO2 to HCO3-?
Carbonic anhydrase
True or false? The parasympathetic nervous system has very little effect on arteriolar dilation or constriction.
True
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?
Granulosa cell
What hormone acts on Granulosa cells?
FSH
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.
What hormone constricts afferent and efferent arterioles (efferent more so) in an effort to preserve glomerular capillary pressure as the renal blood flow decreases?
AT II
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 is the effect of insulin on protein storage?
Insulin increases total body stores of protein, fat, and CHOs. When you think insulin, you think storage.
What is the term for an inhibitory interneuron?
Renshaw neuron
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
300 mOsm/L
What are the following changes seen in the luminal fluid by the time it leaves the PCT of the nephron?
• Concentration of CHO, AA, ketones, peptides
No CHO, AA, ketones, or peptides are left in the tubular lumen.
True or false? Enterokinase is a brush border enzyme.
False. It is an enzyme secreted by the lining of the small intestine.
Where does the synthesis of ACh occur?
In the cytoplasm of the presynaptic nerve terminal; it is catalyzed by choline acetyltransferase.
What pancreatic islet cell secretes somatostatin?
delta-Cells; somatostatin has an inhibitory effect on alpha- and Beta-islet cells.
Why is O2 content depressed in anemic patients?
Anemic patients have a depressed O2 content because of the reduced concentration of Hgb in the blood. As for polycythemic patients, their O2 content is increased because of the excess Hgb concentrations.
What term describes the volume of plasma from which a substance is removed over time?
Clearance
If capillary hydrostatic pressure is greater than oncotic pressure, is filtration or reabsorption promoted?
Filtration; if hydrostatic pressure is less than oncotic pressure, reabsorption is promoted.
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 signal to open the voltage-gated transmembrane sodium channels?
Membrane depolarization is the stimulus to open these channels, which are closed in resting conditions.
What hormones are produced in the median eminence region of the hypothalamus and the posterior pituitary gland?
None; they are the storage sites for ADH and oxytocin.
What is the most energy-demanding phase of the cardiac cycle?
Isovolumetric contraction
What presynaptic receptor does NE use to terminate further neurotransmitter release?
alpha2-Receptors
Are salivary secretions hypertonic, hypotonic, or isotonic?
Hypotonic, because NaCl is reabsorbed in the salivary ducts
What is the effect of T3 on heart rate and cardiac output?
T3 increases both heart rate and cardiac output by increasing the number of Beta-receptors and their sensitivity to catecholamines.
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)
Why is spermatogenesis decreased with anabolic steroid therapy?
Exogenous steroids suppress LH release and result in Leydig cell atrophy. Testosterone, produced by Leydig cells, is needed for spermatogenesis.
What type of membrane is characterized as being permeable to water only?
Semipermeable membrane; a selectively permeable membrane allows both water and small solutes to pass through its membrane.
What thyroid enzyme is needed for oxidation of I– to I'?
Peroxidase, which is also needed for iodination and coupling inside the follicular cell
What is the most important stimulus for the secretion of insulin?
An increase in serum glucose levels
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
What adrenal enzyme deficiency results in hypertension, hypernatremia, and virilization?
11-Beta-Hydroxylase deficiency results in excess production of 11-deoxycorticosterone, a weak mineralocorticoid. It increases BP, Na+, and ECF volume along with production of adrenal androgens.
What is the term for diffusion of water across a semipermeable or selectively permeable membrane?
Osmosis; water will diffuse from higher to lower water concentrations.
When do hCG concentrations peak in pregnancy?
In the first 3 months
How many milliliters of O2 per milliliter of blood?
0.2
What type of cell is surrounded by mineralized bone?
Osteocyte
What two forces affect movement of ions across a membrane?
Concentration force and electrical force
What happens to the resistance of the system when a resistor is added in a series?
Resistance of the system increases. (Remember, when resistors are connected in a series, the total of the resistance is the sum of the individual resistances.)
What is the greatest component of lung recoil?
Surface tension; in the alveoli, it is a force that acts to collapse the lung.
Where is ADH synthesized?
In the supraoptic nuclei of the hypothalamus; it is stored in the posterior pituitary gland.
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 forms of fatty acids are absorbed from the small intestine mucosa by simple diffusion?
Short-chain fatty acids
What is the term for the day after the LH surge in the female cycle?
Ovulation
The opening of what valve indicates the beginning of the ejection phase of the cardiac cycle?
Opening of the aortic valve terminates the isovolumetric phase and begins the ejection phase of the cardiac cycle.
What is the region of an axon where no myelin is found?
Nodes of Ranvier
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.
What day of the menstrual cycle does ovulation take place?
Day 14
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?
Theca cell
What is the main factor determining FF?
Renal plasma flow (decrease flow, increase FF)
Where is the action potential generated on a neuron?
Axon hillock
If free water clearance (CH2O) is positive, what type of urine is formed? And if it is negative?
If positive, hypotonic urine (osmolarity <300 mOsm/L); if negative, hypertonic urine (osmolarity > 300 mOsm/L)>>
What cell in the heart has the highest rate of automaticity?
SA node; it is the reason it is the primary pacemaker of the heart.
What is pumped from the lumen of the ascending loop of Henle to decrease the osmolarity?
NaCl is removed from the lumen to dilute the fluid leaving the loop of Henle.
True or false? In skeletal muscle relaxation is an active event.
True. Sarcoplasmic calcium-dependent ATPase supplies the energy to terminate contraction, and therefore it is an active process.
What three factors increase simple diffusion?
1. Increased solubility
2. Increased concentration gradient
3. Decreased thickness of the membrane
What is the pancreatic action of CCK?
CCK stimulates the pancreas to release amylase, lipase, and proteases for digestion.
What is the rate-limiting step in a conduction of a NMJ?
The time it takes ACh to diffuse to the postjunctional membrane
Is excretion greater than or less than filtration for net secretion to occur?
Excretion is greater than filtration for net secretion to occur.
What acid-base disturbance is produced from vomiting?
Hypokalemic metabolic alkalosis occurs from vomiting because of the loss of H+, K+, and Cl-.
What phase of the menstrual cycle is dominated by estrogen? Progesterone?
Follicular phase is estrogen-dependent with increased FSH levels, while the luteal phase is progesterone-dependent.
Name the lung measurement based on the following descriptions:
• The amount of air that enters or leaves the lung system in a single breath
Tidal volume (VT)
Name the lung measurement based on the following descriptions:
• The maximal volume inspired from FRC
Inspiratory capacity
Name the lung measurement based on the following descriptions:
• Additional volume that can be expired after normal expiration
Expiratory reserve volume (ERV)
Name the lung measurement based on the following descriptions:
• Maximal volume that can be expired after maximal inspiration
Vital capacity (VC)
Name the lung measurement based on the following descriptions:
• Volume in the lungs at the end of passive expiration
Functional residual capacity (FRC)
Name the lung measurement based on the following descriptions:
• Additional air that can be taken in after normal inspiration
Inspiratory reserve volume (IRV)
Name the lung measurement based on the following descriptions:
• Amount of air in the lungs after maximal expiration
Residual volume (RV)
Name the lung measurement based on the following descriptions:
• Amount of air in the lungs after maximal inspiration
Total lung capacity (TLC)
What growth factors are chondrogenic, working on the epiphyseal end plates of bone?
Somatomedins (IGF-1)
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.
True
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.
What is the respiratory compensation mechanism for metabolic alkalosis?
Hypoventilation, which increases CO2, shifting the reaction to the right and increasing H+
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?
Subthreshold potential
What three organs are responsible for peripheral conversion of T4 to T3?
Liver, kidneys, and pituitary gland via 5' deiodinase enzyme
The closure of what valve indicates the beginning of isovolumetric contraction?
Mitral valve closure indicates the termination of the ventricular filling phase and beginning of isovolumetric contraction.
How many carbons do androgens have?
Androgens are 19-carbon steroids.
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 cm H2O (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?
Estriol
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?
1. Liver
2. Kidney
3. Pituitary gland (via 5'-deiodinase enzyme)
Using Laplace's relationship regarding wall tension, why is the wall tension in an 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.
To what is the diffusion rate indirectly proportional?
Diffusion rate is indirectly proportional to membrane thickness and is directly proportional to membranes surface area.
ADH is secreted in response to what two stimuli?
ADH is secreted in response to increased plasma osmolarity and decreased blood volume.
What vessels have the largest total cross-sectional area in systemic circulation?
Capillaries
How many days before the first day of menstrual bleeding is ovulation?
14 days in most women (Remember, the luteal phase is always constant.)
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 subunit of hCG is used to detect whether a patient is pregnant?
The β-subunit; remember, the α-subunit is nonspecific.
What happens to capillary oncotic pressure with dehydration?
Oncotic pressure increases because of the removal of water.
What cells of the kidney are extravascular chemoreceptors for decreased Na+, Cl-, and NaCl?
Macula densa
What is the effect of insulin on intracellular K+ stores?
Insulin increases intracellular K+ stores while decreasing serum K+ levels.
What triggers phase 4 of the action potential in a ventricular pacemaker cell?
Decreasing potassium conductance, which results in increased excitability
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 name of the regulatory protein that covers the attachment site on actin in resting skeletal muscle?
Tropomyosin
Which way does the Hgb-O2 dissociation curve shift in patients with CO poisoning?
The pathologic problem with CO poisoning is that CO has 240 times as much affinity for Hgb molecule as does O2, reducing the carrying capacity and shifting the curve to the left, making it difficult to remove the CO molecule from Hgb.
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 cells of the thyroid gland are stimulated in response to hypercalcemia?
The parafollicular cells of the thyroid (C cells) release calcitonin in response to hypercalcemia.
What is the term for the amount of blood in the ventricle after maximal contraction?
Residual volume
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 renal plasma flow?
Para-aminohippurate (PAH)
What bile pigment is formed by the metabolism of bilirubin by intestinal bacteria, giving stool its brown color?
Stercobilin
Is ACh associated with bronchoconstriction or bronchodilation?
Bronchoconstriction is associated with parasympathetic stimulation (ACh), and catecholamine stimulation is associated with bronchodilation (why epinephrine is used in emergency treatment of bronchial asthma.)
What are the growth factors released from the liver called?
Somatomedins
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 happens to extracellular volume with a net gain in body fluid?
The ECF compartment always enlarges when there is a net gain in total body water and decreases when there is a loss of total body water. Hydration status is named in terms of the ECF compartment.
What are the six substances that promote the secretion of insulin?
1. Glucose
2. Amino acid (arginine)
3. Gastrin inhibitory peptide (GIP)
4. Glucagon
5. β-Agonists
6. ACh
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. CO 2 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?
Urinary 17-ketosteroids
How are resistance and length related regarding flow?
Resistance and vessel length are proportionally related. The greater the length of the vessel, the greater the resistance is on the vessel.
Is filtration greater than or less than excretion for net reabsorption to occur?
Filtration is greater than excretion for net reabsorption to occur.
What hormone, stimulated by epinephrine, results in an increase in lipolysis?
Hormone-sensitive lipase, which breaks down triglyceride into glycerol and free fatty acid
True or false? Miniature end-plate potentials (MEPPs) generate action potentials.
False
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 neurons innervate the striated muscle of the bulbospongiosus and ischiocavernous muscles and result in ejaculation of semen.
True
What happens to intraventricular pressure and volume during isovolumetric contraction?
As the name indicates, there is no change in volume but there is an increase in pressure.
Do high levels of estrogen and progesterone block milk synthesis?
Yes, they stimulate the growth of mammary tissue but block milk synthesis. At parturition, the decrease in estrogen lifts the block on milk production.
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.
In what type of circuit is the total resistance always less than that of the individual resistors?
Parallel circuit
What is the term for days 15 to 28 in the female cycle?
Luteal phase
What happens to total and alveolar ventilation with
• Increased rate of breathing?
With an increased rate of breathing the total ventilation is greater than the alveolar ventilation. Rapid, shallow breathing increases dead space ventilation with little change in alveolar ventilation. (This is hypoventilation).
What happens to total and alveolar ventilation with
• Increased depth of breathing?
With an increased depth of breathing both the total and alveolar ventilation increase.

This concept is always tested on the boards, so remember it.
What pathophysiologic disorder is characterized by the following changes in cortisol and ACTH?
• Cortisol decreased, ACTH increased
Primary hypocortisolism (Addison's disease)
What pathophysiologic disorder is characterized by the following changes in cortisol and ACTH?
• Cortisol increased, ACTH increased
Secondary hypercortisolism (pituitary)
What pathophysiologic disorder is characterized by the following changes in cortisol and ACTH?
• Cortisol increased, ACTH decreased
Primary hypercortisolism
What pathophysiologic disorder is characterized by the following changes in cortisol and ACTH?
• Cortisol decreased, ACTH decreased
Secondary hypocortisolism (pituitary)
What happens to flow and pressure in capillaries with arteriolar dilation? Arteriolar constriction?
Capillary flow and pressure increase with arteriolar dilation and decrease with arteriolar constriction.
What has occurred to the renal arterioles based on the following changes in the GFR, RPF, FF, and glomerular capillary pressure?
• GFR ↑, RPF ↑, FF normal, capillary pressure ↑
Dilation of afferent arteriole
What has occurred to the renal arterioles based on the following changes in the GFR, RPF, FF, and glomerular capillary pressure?
• GFR ↑, RPF ↓, FF ↑, capillary pressure ↑
Constriction of efferent arteriole
What has occurred to the renal arterioles based on the following changes in the GFR, RPF, FF, and glomerular capillary pressure?
• GFR ↓, RPF ↑, FF ↓, capillary pressure ↓
Dilation of efferent arteriole
What has occurred to the renal arterioles based on the following changes in the GFR, RPF, FF, and glomerular capillary pressure?
• GFR ↓, RPF ↓, FF normal, capillary pressure ↓
Constriction of afferent arteriole
Which direction is air flowing when the intra-alveolar pressure is zero?
When the intra-alveolar pressure equals zero, there is no airflow.
What phase of the female cycle occurs during days 1 to 15?
Follicular phase
What determines the effective osmolarity of the ICF and the ECF compartments?
The concentration of plasma proteins determines effective osmolarity because capillary membranes are freely permeable to all substances except proteins.
What region of the brain houses the central chemoreceptors responsible for control of ventilation?
The surface of the medulla
What is the site of action of cholera toxin?
Cholera toxin irreversibly activates the cAMP-dependent chloride pumps of the small and large intestine, producing a large volume of chloride-rich diarrhea.
Name the phase of the ventricular muscle action potential based on the following information:
• Slow channels open, allowing calcium influx; voltage-gated potassium channels closed; potassium efflux through ungated channels; plateau stage
Phase 2
Name the phase of the ventricular muscle action potential based on the following information:
• Slight repolarization secondary to potassium and closure of the sodium channels
Phase 1
Name the phase of the ventricular muscle action potential based on the following information:
• Fast channels open, then quickly close, and sodium influx results in depolarization
Phase 0
Name the phase of the ventricular muscle action potential based on the following information:
• Slow channels close, voltage-gated potassium channels reopen with a large influx of potassium, and the cell quickly repolarizes
Phase 3
Where in the kidney are the long loops of Henle and the terminal regions of the collecting ducts?
In the medulla; all the other structures are cortical.
What is absorbed in the gallbladder to concentrate bile?
Water
What type of hormone is described as having intracellular receptors, being synthesized as needed, mostly bound to proteins, and having its activity determined by free hormone levels?
Lipid-soluble hormones are considered slow-acting hormones.
What are the three stimuli that result in the reninangiotensin-aldosterone secretion?
1. Low pressure in the afferent renal arteriole
2. Low sodium sensed by the macula densa
3. Increased β-1-sympathetic stimulation of the JG cells
Is there a shift in p50 values with anemia? Polycythemia?
The p50 value does not change in either anemia or polycythemia; the main change is the carrying capacity of the blood.
What hormone level peaks 1 day before the surge of LH and FSH in the female cycle?
Estradiol
True or false? Active protein transport requires a concentration gradient.
True; it requires both a concentration gradient and ATP to work.
Up to how many hours post ejaculation do sperm retain their ability to fertilize the ovum?
Up to 72 hours; the ovum losses its ability to be fertilized 8 to 25 hours after release.
What type of membrane channel opens in response to depolarization?
Voltage-gated channel
What are the five effects of insulin on fat metabolism?
1. Increased glucose uptake by fat cells
2. Increased triglyceride uptake by fat cells
3. Increased conversion of CHOs into fat
4. Decreased lipolysis in fat tissue
5. Decreased ketone body formation
True or false? In a skeletal muscle fiber, the interior of the T-tubule is extracellular.
True. They are evaginations of the surface membranes and therefore extracellular.
Under resting conditions, what is the main determinant of cerebral blood flow?
Arterial PCO2 levels are proportional to cerebral blood flow.
On the venous pressure curve, what do the following waves represent?
• A wave?
Atrial contraction

Atrial, Contraction, Venous
On the venous pressure curve, what do the following waves represent?
• C wave?
Ventricular contraction

Atrial, Contraction, Venous
On the venous pressure curve, what do the following waves represent?
• V wave?
Atrial filling (venous filling)
Atrial, Contraction, Venous
What cell type in the bone is responsible for bone deposition?
Osteoblast (Remember, blasts make, clasts take)
True or false? The blood stored in the systemic veins and the pulmonary circuit are considered part of the cardiac output.
False. Cardiac output refers to circulating blood volume. The blood in the systemic veins and the pulmonary circuits are storage reserves and therefore are not considered in cardiac output.
What hormone disorder is characterized by the following abnormalities in sex steroids↓, LH↓, and FSH↓?
• Sex steroids , LH , FSH
Pituitary hypogonadism
What hormone disorder is characterized by the following abnormalities in sex steroids, LH, and FSH?
• Sex steroids ↑, LH ↓, FSH ↓?
GnRH constant infusion
What hormone disorder is characterized by the following abnormalities in sex steroids↓, LH↑, and FSH↑?
• Sex steroids , LH , FSH ?
Primary hypogonadism (postmenopausal women)
What are the three characteristics of autoregulation?
1. Flow independent of BP
2. Flow proportional to local metabolism
3. Flow independent of nervous reflexes
What is the fastest-conducting fiber of the heart? Slowest conduction fiber in the heart?
Purkinje cell is the fastest, and the AV node is the slowest.
What equals the total tension on a muscle minus the preload?
Afterload
What follicular cell possesses FSH receptors and converts androgens into estradiol?
Granulosa cells
What are the primary neurotransmitters at the following sites?
• Postganglionic sympathetic neurons
NE
What are the primary neurotransmitters at the following sites?
• Chromaffin cells of the adrenal medulla
Epinephrine
What are the primary neurotransmitters at the following sites?
• Brainstem cells
Serotonin
What are the primary neurotransmitters at the following sites?
• The hypothalamus
Histamine
What are the primary neurotransmitters at the following sites?
• All motor neurons, postganglionic parasympathetic neurons
ACh
What are the primary neurotransmitters at the following sites?
• Autonomic preganglionic neurons
ACh
What region of the nephron has the highest osmolarity?
Tip of the loop of Henle (1200 mOsm/L)
What pH (acidotic or alkalotic) is needed for pepsinogen to pepsin conversion?
Acid is needed for the activation of pepsin and therefore needed for protein digestion.
What is the term for the amount of blood expelled from the ventricle per beat?
Stroke volume
True or false? Oxytocin initiates rhythmic contractions associated with labor.
False. It does increase uterine synthesis of prostaglandins, which increase uterine contractions.
Why does carbon monoxide diffusion in the lung (DLCO) decrease in emphysema and fibrosis but increase during exercise?
DLCO, an index of lung surface area and membrane thickness, is decreased in fibrosis because of increased membrane thickness and decreased in emphysema because of increased surface area without increase in capillary recruitment; in exercise there is an increase in surface area due to capillary recruitment.
What enzyme converts androgens to estrogens?
Aromatase
The clearance of what substance is the gold standard of GFR?
Inulin
How does myelination affect conduction velocity of an action potential?
The greater the myelination, the greater the conduction velocity.
What are the three end products of amylase digestion?
1. Maltose
2. Maltotetrose
3. α-Limit dextrans (α-1, 6 binding)
Where is most of the airway resistance in the respiratory system?
In the first and second bronchi
What is the respiratory compensation mechanism for metabolic acidosis?
Hyperventilation, which decreases CO2, shifting the reaction to the left and decreasing H+
How are resistance and viscosity related regarding flow?
Viscosity and resistance are proportionally related. The greater the viscosity, the greater the resistance is on the vessel.
T3 increases bone ossification through synergistic effect with what hormone?
GH
Name the ventricular muscle membrane channel:
• Closed at rest; depolarization causes channels to open slowly
Voltage-gated calcium channel
Name the ventricular muscle membrane channel:
• Always open
Ungated potassium channel
Name the ventricular muscle membrane channel:
• Closed at rest; depolarization causes channels to open quickly; will not respond to a second stimulus until cell is repolarized.
Voltage-gated sodium channel
Name the ventricular muscle membrane channel:
• Open at rest; depolarization is stimulus to close; begin to reopen during the plateau phase and during repolarization
Voltage-gated potassium channels
What are the three glycogenic organs?
Liver, kidney, and GI epithelium
Is CO2 a perfusion-or diffusion-limited O2 gas?
Since CO2 is 24 times as soluble as O2, the rate at which CO2 is brought to the membrane determines its rate of exchange, making it perfusion-limited a gas. For O2 the more time it is in contact with the membrane, the more likely it will diffuse, making it diffusion-limited.
What is the term for the potential difference across a cell membrane?
Transmembrane potential (an absolute number)
What adrenal enzyme deficiency can be summed up as a mineralocorticoid deficiency, glucocorticoid deficiency, and an excess of adrenal androgens?
21-β-Hydroxylase deficiency leads to hypotension, hyponatremia, and virilization.
When the ECF osmolarity increases, what happens to cell size?
Increase in ECF osmolarity means a decrease in ICF osmolarity, so cells shrink.
When does cortisol secretion peak?
In early-morning sleep, usually between the sixth and eighth hours
What is the term for ventilation of unperfused alveoli?
Alveolar dead space
What is the bioactive form of thyroid hormone?
T3
What acid-base disturbance occurs in colonic diarrhea
Hypokalemic metabolic acidosis occurs in colonic diarrhea because of the net secretion of HCO3- and potassium into the colonic lumen.
What two AAs act as excitatory transmitters in the CNS, generating EPSPs?
Glutamine and aspartate
What are the three mechanisms of action for atrial natriuretic peptide's diuretic and natriuretic affects?
1. Dilation of the afferent arteriole
2. Constriction of the efferent arteriole
3. Inhibition of reabsorption of sodium and water in the collecting ducts
In a parallel circuit, what happens to resistance when a resistor is added in parallel
Resistance decreases as resistors are added in parallel.
What component of the ANS is responsible for movement of semen from the epididymis to the ejaculatory ducts?
Sympathetic nervous system
What happens to O2 affinity with a decrease in p50?
O2 affinity increases with a decrease in the p50, making O2 more difficult to remove from the Hgb molecule.
If the ratio of a substance's filtrate and plasma concentrations are equal, what is that substance's affect on the kidney?
If the ratio of the filtrate to plasma concentration of a substance is equal, the substance is freely filtered by the kidney.
What does a loss of afferent activity from the carotid sinus onto the medulla signal?
A loss of afferent activity indicates a decrease in BP, and an increase in afferent activity indicates an increase in BP.
What are the five F's associated with gallstones?
1. Fat
2. Forty
3. Female
4. Familial
5. Fertile
True or false? Menstruation is an active process due to increased gonadal sex hormones?
False. It is a passive process due to decreased sex hormones.
What happens to the intrapleural pressure when the diaphragm relaxes?
Relaxation of the diaphragm increases the intrapleural pressure (becomes more positive).
What component of the renin-angiotensin-aldosterone axis increases sodium reabsorption in the proximal convoluted tubules and increases thirst drive?
AT II
What large-diameter vessel has the smallest cross-sectional area in systemic circulation?
The aorta
Excess bone demineralization and remodeling can be detected by checking urine levels of what substance?
Hydroxyproline (breakdown product of collagen)
What happens to the following during skeletal muscle contraction?
• A band
No change in length
What happens to the following during skeletal muscle contraction?
• I band
Shortens
What happens to the following during skeletal muscle contraction?
• H zone
Shortens
What happens to the following during skeletal muscle contraction?
• Sarcomere
Shortens
What happens to the following during skeletal muscle contraction?
• Actin and myosin lengths
No change in length
What are the three effects of insulin on protein metabolism?
1. Increased amino acid uptake by muscles
2. Decreased protein breakdown
3. Increased protein synthesis
What is the main mechanism for exchange of nutrients and gases across a capillary membrane?
Simple diffusion; it does not use protein-mediated transport
What event signifies the first day of the menstrual cycle?
Onset of bleeding
Name the muscle type based on the histological features:
• Actin and myosin in sarcomeres; striated; uninuclear; gap junctions; troponin:calcium binding complex; T tubules and SR forming dyadic contacts; voltage-gated calcium channels
Cardiac muscle
Name the muscle type based on the histological features:
• Actin and myosin in sarcomeres; striated; multinuclear; lacks gap junctions; troponin:calcium binding; T tubules and SR forming triadic contacts; highest ATPase activity; no calcium channels
Skeletal muscle
Name the muscle type based on the histological features:
• Actin and myosin not in sarcomeres; nonstriated; uninuclear; gap junctions; calmodulin:calcium binding; lacks T tubules; voltage-gated calcium channels
Smooth muscle
Name the valve abnormality based on the following criteria:
• Back-filling into the left atrium during systole; increased v-wave, preload, left atrial volume, and left ventricular filling
Mitral insufficiency
Name the valve abnormality based on the following criteria:
• Systolic murmur, increased preload and afterload, decreased aortic pulse pressure and coronary blood flow
Aortic stenosis
Name the valve abnormality based on the following criteria:
• Diastolic murmur, increased right ventricular pressure, left atrial pressure, and atrial to ventricular pressure gradient; decreased left ventricular filling pressure
Mitral stenosis
Name the valve abnormality based on the following criteria:
• Diastolic murmur; increased preload, stroke volume, and aortic pulse pressure; decreased coronary blood flow; no incisura; and peripheral vasodilation
Aortic insufficiency
Circulating levels of what hormone cause the cervical mucus to be thin and watery, allowing sperm an easier entry into the uterus?
Estrogen
What hormone controls relaxation of the lower esophageal sphincter during swallowing?
VIP is an inhibitory parasympathetic neurotransmitter that results in relaxation of the lower esophageal sphincter.
What is the term for the difference between systolic and diastolic pressures?
Pulse pressure
What hormone, produced by the Sertoli cells, is responsible for keeping testosterone levels in the seminiferous tubules nearly 50 times that of the serum?
Androgen-binding protein
True or false? There are no central O2 receptors.
True
What cell type of the bone has PTH receptors?
Osteoblasts, which in turn stimulate osteoclasts to break down bone, releasing Ca2+ into the interstitium. (Remember, blasts make, clasts take.)
What substance is secreted by parietal glands and is required for life?
Intrinsic factor (IF)
What is the only way to increase O2 delivery in the coronary circulation?
Increasing blood flow is the only way to increase O2 delivery in the coronary circulation because extraction is nearly maximal during resting conditions.
What is the term for the load a muscle is trying to move during stimulation?
Afterload
What is the term for days 1 to 7 of the female cycle?
Menses
What is the term for the force the ventricular muscle must generate to expel the blood into the aorta?
Afterload
What happens to the tonicity of the urine with increased ADH secretion?
The urine becomes hypertonic because of water reabsorption in the collecting duct.
What form of renal tubular reabsorption is characterized by high back leak, low affinity for substance, and absence of saturation and is surmised to be a constant percentage of a reabsorbed filtered substance?
Gradient-time system
What type of circuit is described when the total resistance is always greater than the sums of the individual resistors?
Series circuit
What hormone excess brings about abnormal glucose tolerance testing, impaired cardiac function, decreased body fat, increased body protein, prognathism, coarse facial features, and enlargements of the hands and feet?
Increased secretion of GH postpuberty leading to acromegaly.
What happens to V/Q ratio if a thrombus is lodged in the pulmonary artery?
The V/Q ratio increases, since the area is ventilated but hypoperfused as a result of the occlusion.
What hormone has the following effects: chondrogenic in the epiphyseal end plates of bones; increases AA transport for protein synthesis; increases hydroxyproline (collagen); and increases chondroitin sulfate synthesis?
GH, especially IGF-1. GH also increases the incorporation of thymidine in DNA synthesis and uridine in RNA synthesis.
True or false? Bile pigments and bile salts are reabsorbed in the gallbladder.
False
What component of an ECG is associated with the following?
• Conduction delay in the AV node
PR interval
What component of an ECG is associated with the following?
• Ventricular depolarization
QRS complex
What component of an ECG is associated with the following?
• Atrial depolarization
P wave
What component of an ECG is associated with the following?
• Ventricular repolarization
T wave
Where is the greatest venous PO2 in resting tissue?
Renal circulation
Near the end of pregnancy, what hormone's receptors increase in the myometrium because of elevated plasma estrogen levels?
Oxytocin
What respiratory center in the rostral pons has an inhibitory affect on the apneustic center?
Pneumotaxic center (short, fast breaths)
For what hormone do Leydig cells have receptors?
LH
What primary acid-base disturbance is cause by a decrease in alveolar ventilation (increasing CO2 levels) resulting in the reaction shifting to the right and increasing H+ and HCO3- levels?
Respiratory acidosis (summary: high CO2, high H+, slightly high HCO3-)
What lecithin: sphingomyelin ratio indicates lung maturity?
2.0 or greater
What is the term for the negative resting membrane potential becoming more negative?
Hyperpolarization (i.e., K+ influx)
What type of resistance system (i.e., high or low) is formed when resistors are added in parallel?
A low-resistance system is formed by resistors added in parallel.
Why is hypothyroidism associated with night blindness?
Thyroid hormones are necessary for conversion of carotene to vitamin A.
What is the FiO2 of room air?
0.21; it is a fancy way of saying 21% of the air is O2.
Where are the lowest resting PO2 levels in a resting individual?
Coronary circulation
What is the rate-limiting step in the production of steroids?
The conversion of CHO to pregnenolone via the enzyme desmolase
In the water deprivation test, does a patient with reduced urine flow have primary polydipsia or diabetes insipidus?
Primary polydipsia; patients with diabetes insipidus will continue to produce large volumes of dilute urine.
True or false? There is an inverse relationship between fat content and total body water.
True; the greater the fat, the less the total body water.
What is the role of the negative charge on the filtering membrane of the glomerular capillaries?
The negative charge inhibits the filtration of protein anions.
What cardiac reflex is characterized by stretch receptors in the right atrium, afferent and efferent limbs via the vagus nerve, and increased stretch leading to an increase in heart rate via inhibition of parasympathetic stimulation?
Bainbridge reflex
Where in the GI tract does the reabsorption of bile salts take place?
Bile salts are actively reabsorbed in the distal ileum.
What three structures increase the surface area of the GI tract?
1. Plicae circularis (3 times)
2. Villi (30 times)
3. Microvilli (600 times)
Does physiologic splitting of the first heart sound occur during inspiration or expiration? Why?
Splitting of the first heart sound occurs during inspiration because of the increased output of the right ventricle, delaying the closure of the pulmonic valve.
How much dietary iodine is necessary to maintain normal thyroid hormone secretion?
150 mcg/day is the minimal daily intake needed. Most people ingest 500 mcg/day.
What is the central chemoreceptor's main drive for ventilation?
CSF H+ levels, with acidosis being the main central drive, resulting in hyperventilation (the opposite being true with alkalosis)
What result occurs because of the negative alveolar pressure generated during inspiration?
Air flows into the respiratory system.
Corticotropin-releasing hormone promotes the synthesis and release of what prohormone?
Pro-opiomelanocortin (POMC) is cleaved into ACTH and β-lipotropin.
What happens to free hormone levels when the liver decreases production and release of binding proteins?
Free hormone levels remain constant, and the bound hormone level changes with a decrease in binding hormones.
What type of estrogen is produced in peripheral tissues from androgens?
Estrone
What changes does more negative intrathoracic pressure cause to systemic venous return and to the pulmonary vessels?
Promotes systemic venous return into the chest and increases the caliber and volume of the pulmonary vessels
Where is renin produced?
In the JG cells of the kidney
True or false? Right-sided valves close before the valves on the left side of the heart.
False. Right-sided valves are the first to open and last to close.
What enzyme is associated with osteoblastic activity?
Alkaline phosphatase
What is the order of attachment of O2 to Hgb-binding sites in the lung? Order of release from the binding sites in the tissue?
Order of attachment is site 1, 2, 3, 4, and for release is 4, 3, 2, 1.
What hormone is secreted into the plasma in response to a meal rich in protein or CHO?
Insulin
What happens to blood flow and pressure downstream with local arteriolar constriction?
With arteriolar constriction both the flow and pressure downstream decrease.
What occurs when the lower esophageal sphincter fails to relax during swallowing due to abnormalities of the enteric nervous plexus?
Achalasia
True or false? Ungated channels are always open.
True. They have no gates, so by definition they are always open.
What component of the ANS is responsible for dilation of the blood vessels in the erectile tissue of the penis, resulting in an erection?
Parasympathetics (parasympathetics point, sympathetics shoot)
What muscle type is characterized by low ATPase activity, aerobic metabolism, myoglobin, association with endurance, and small muscle mass?
Red muscle
What happens to diastolic and systolic intervals with an increase in sympathetic activity?
Systolic interval decreases secondary to increased contractility; diastolic interval decreases secondary to an increase in heart rate.
Circulating levels of what hormone in men is responsible for the negative feedback loop to the hypothalamus and the anterior pituitary gland regulating the release of LH?
Testosterone
How are pulse pressure and compliance related?
They are inversely proportional to each other; as pulse pressure increases, compliance decreases.
What three substances stimulate parietal cells?
ACh, histamine, and gastrin
What two factors result in the base of the lung being hyperperfused?
Increased pulmonary arterial pressure (high perfusion) and more distensible vessels (low resistance) result in increased blood flow at the base.
True or false? Without ADH the collecting duct would be impermeable to water.
True. Without ADH hypotonic urine would be formed.
How does ventricular depolarization take place, base to apex or vice versa?
Depolarization is from apex to base and from endocardium to epicardium.
What are effects of PTH in the kidney?
PTH increases Ca2+ reabsorption in the DCT of the kidney and decreases PO4- reabsorption in the PCT.
Regarding muscle mechanics, how is passive tension produced?
It is produced by the preload on the muscle prior to contraction.
Insulin-induced hypoglycemia is the most reliable (by far not the safest) test for what hormone deficiency?
GH deficiency
In regards to solute concentration, how does water flow?
Water flows from a low-solute to high-solute concentrations.
Which extravascular chemoreceptor detects low NaCl concentrations?
Macula densa
If the AV difference is positive, is the substance extracted or produced by the organ?
A positive AV difference indicates that a substance is extracted by the organ, and a negative difference indicates that it is produced by the organ.
What is used as an index of the number of functioning carriers for a substance in active reabsorption in the kidney?
Transport maximum (Tm) occurs when all function carriers are saturated and therefore is an index of the number of functioning carriers.
Why is there a transcellular shift in K+ levels in a diabetic patient who becomes acidotic?
The increased H+ moves intracellularly and is buffered by K+ leaving the cells, resulting in intracellular depletion and serum excess. (Intracellular hypokalemia is the reason you supplement potassium in diabetic ketoacidosis, even though the serum levels are elevated.)
True or false? Catechol-O-methyl transferase (COMT) is not found in smooth muscle, liver, and the kidneys.
False. That is precisely where COMT is found; it is not found in adrenergic nerve terminals.
What somatomedin serves as a 24-hour marker of GH secretion?
IGF-1 (somatomedin C)
What receptor is in the smooth muscle cells of the small bronchi, is stimulated during inflation, and inhibits inspiration?
Stretch receptors prevent overdistension of the lungs during inspiration.
True or false? Thyroid hormones are necessary for normal menstrual cycles.
True. They are also necessary for normal brain maturation.
What component of the cardiovascular system has the largest blood volume? Second largest blood volume?
The systemic veins have the largest blood volume, and the pulmonary veins have the second largest blood volume in the cardiovascular system. They represent the reservoirs of circulation.
Serum concentration of what substance is used as a clinical measure of a patient's GFR?
Creatinine
Where does CHO digestion begin?
In the mouth with salivary α-amylase (ptyalin)
How does the sympathetic nervous system affect insulin secretion?
It decreases insulin secretion.
How does cell diameter affect the conduction velocity of an action potential?
The greater the cell diameter, the greater the conduction velocity.