HBY531 Organ Systems
Final Examination 1996
SECTION 1: Answer the following using:
A =Increase
B =Remain the same or no change
C=Decrease
1. After a meal plasma levels of apo B-48_____________ .
2. In patients with a deficiency of the plasma enzyme LCAT, plasma levels
of apo CII are expected to_____________.
3. After removal of the ileal region of the intestine, bile acid uptake
will_____________ .
4. High concentrations of VLDL in plasma with low concentrations of LDL
suggests a(n)_____________in lipoprotein lipase activity .
5. In a patient 4 hours after a high fat meal, plasma chylomicra are _____________ compared to fasting levels.
6.The slow wave activity within the muscularis externa of the small intestine will _____________ with increased parasympathetic input.
7. Acid secretion by parietal cells will _____________ in the presence of Cholesystokinin (CCK).
8. The diameter of the Sphincter of Oddi will _____________in response to CCK.
9. The contractile activity of smooth muscle cells in the muscularis externa in the colon will _____________ in response to gastrin.
10. The diameter of the ileocolonic sphincter will _____________ in response to secretin.
11. Within the columnar absorptive cell if the intracellular sodium increased from 15 mM to 45 mM the rate at which glucose was absorbed would _____________.
12. Lipoprotein lipase activity will ___________ with an increase in blood glucose.
13. Glucagon secretion by pancreatic alpha cells will ___________ with an increase in blood glucose.
14. As the pH of blood increases from 7.4 to 7.7, the percentage of total calcium circulating in blood as free ionized Ca2+ will __________.
15. In cell cultures containing osteoblasts and osteoclast precursors, the ratio of osteoclasts/macrophages formed will __________ when macrophage colony stimulating factor is present only in soluble form.
16. During primary hyperparathyroidism, the plasma [Ca2+] at which PTH secretion is half-maximal will __________ relative to normal.
17. The intracellular concentration of calbindins in columnar absorptive cells of the small intestine will __________ following calcitriol treatment (assayed 16 hours following treatment).
18. Plasma [Ca2+] will __________ when measured 24 hours following surgical removal of the thyroid gland.
19. The secretion rate of sex-steroid binding globulin (SSBG) will __________ with testosterone input to hepatocytes.
20. The secretion rate of testosterone will ________ with estradiol input from Sertoli cells.
21. The intracellular concentrations of pyruvate in Sertoli cells will ___________ with FSH input.
For 22 through 25
In the case of chronic adrenal insufficiency:
22. Serum sodium ion concentration will ______________.
23. Blood glucose level is likely to _______________, especially in the fasted state.
24. Blood pressure is likely to _________________.
25. Serum potassium concentration is likely to __________.
SECTION 2: For each of the following statements, choose A if the statement is true, or B if the statement is false.
26. Pancreatic somatostatin inhibits insulin but not glucagon release.
27. LH stimulates progesterone production by granulosa cells of the antral or graafian follicle.
28. Patients with polycystic ovarian disease have high androgens and estrogens. This is associated with high FSH, anovulatory cycles due to poor follicular development and abnormal bleeding.
29. There is a small surge in GnRH secretion at midcycle.
30. Prolactin stimulates continuous growth of the uterine myometrium and development of the ductal tissue in the breast.
SECTION 3: For each of the following choose the single best response
31. A patient complains of bouts of diarrhea over the last six months. The individual indicates he has no restrictions with regard to dietary intake.
a. the patient has ingested materials containing the bacteria Vibrio Cholerae which produces cholera.
b. the patient is suffering from Hartnup’s disease in which neutral amino acids are not transported out of the intestinal lumen and into the cytoplasm of the columnar cells due to the lack for neutral co-transporters.
c. the diarrhea could be caused by drugs which inhibit gastric and intestinal motility.
d. the patient could have lactose intolerance which would require a correlation between the ingestion of dairy products and the onset of symptoms.
32. With regard to secretion, which of the following is incorrect?
a. Bile acids can be secreted by hepatocytes as primary or secondary bile acids.
b. Cl- channels within the crypt cells of the small intestine are activated by cAMP.
c. Na ions are able to diffuse through the tight junctions connecting crypt cells in the small intestine.
d. The salivary glands produce ~ 200 mL of secretions a day.
33. Which of the following is incorrect? Absorption in the small intestine:
a. of glucose is dependent on co-transport with Na+.
b. of Mg++ is saturable.
c. of Fe++ from the lumenal contents requires that it first be bound to transferrin.
d. of K+ by the columnar absorptive cells requires K+ channels on the apical surface.
34. Absorption of amino acids by columnar absorptive cells:
a. in the absence of membrane bound oligopeptidases would be inhibited.
b. in the absence of membrane bound dipeptidases would be inhibited.
c. in the absence of di- and tripeptide transporters would be inhibited.
d. all of the above are true.
35. Pancreatic secretion:
a. has little or no direct autonomic input during the cephalic phase of pancreatic secretion.
b. from acinar cells is governed by the hormone GIP.
c. is never isosmotic with plasma, regardless of flow rate.
d. contains the enzyme dextrinase.
36. Given: A crypt cell in the small intestine contains Cl- channels in its apical membrane and the resting potential of the cell is -60 mV. The extracellular (lumenal) Cl- concentration is 150 mM while the concentration inside the cell is 13.5 mM. [Eion=25mV*ln(Ci/Co) for anions]. Further, the Cl- channels have been activated such that their open probability has gone from 5% to 95%.
a. Ecl=-40 mV
b. The flux of Cl- across the apical membrane is near 0.
c. The flux of Cl- across the apical membrane is outward.
d. None of the above are true.
In GI figure 1 (next page), case A shows data obtained from a normal individual. Stomach pH (open circles), stomach volume (open squares) and duodenal volume (filled squares) are plotted. The arrow indicates when the individual began eating a 1.5 kg meal consisting of 200 g of solid and 1300 ml fluid, pH 7.0 and isosmotic with plasma. The asterisk indicates the point at which the individual stopped eating. Data from a test subject are plotted in case B. The same symbols are used. Again, 1300 ml of fluid and 200 g of solid were consumed. In this case the fluid consumed was pH 6.2 and isosmotic with plasma. The test subject in case C also consumed 1300 ml fluid and 200 g solid. The pH was 7.0, and the fluid was isosmotic with plasma. (Use this figure for questions 37-39).
37. In case B the stomach volume:
a. never increases because the meal was of inadequate size.
b. rapidly declines because the patient has had a vagotomy resulting in the dumping syndrome.
c. rapidly declines because the muscularis externa is tonically contracted and never relaxes.
d. rapidly declines because the pyloric sphincter is dilated by the presence of gastrin.
38. In case C the rate of duodenal filling:
a. could be slow due to the effects of VIP(vasoactive intestinal peptide) on the pyloric sphincter.
b. could be due to a prolonged receptive relaxation reflex lasting 5 hours.
c. could be due to an elevated and presistent presence of secretin in the blood.
d. could be caused by vagatomy.
39. In case A the total ingested material was 1500 grams and the total stomach volume approximately 40 minutes after the termination of ingesting food is 2.2 L.
a. Some of the extra volume in the stomach arises from salivary secretions.
b. Much of the extra volume in the stomach arises from the addition of acid secretions during receptive relaxation.
c. Receptive relaxation is very long (2.5 hours).
d. a and b are correct.
40. Patients lacking microsomal transfer protein:
a. Can not secrete chylomicra
b. Absorb fat poorly
c. Do not secrete apo B-48
d. All of the above
e. None of the above
41. High levels of HDL in plasma indicate:
a. Low levels of LCAT activity
b. High levels of LDL in plasma
c. High levels of apo AI synthesis
d. All of the above
e. None of the above
42. Which of the following would not result from a genetic absence of a functional cortisol receptor?
a. a physiological deficiency state
b. resistance of the patient to the administration of physiological dose of cortisol
c. an increase in the level of the pituitary tropic hormone (ACTH) controlling the production of cortisol by the adrenal gland
d. probable involution of the fasciculata zone of the adrenal gland
43. The following correctly describe features of hormone receptors:
a. increased receptor concentration may result in decreased biological action of a fixed (unchanged) concentration of hormone.
b. it is common for a specific receptor type to down-regulate in response low concentrations (lower than the physiological range) of their specific hormone
c. there are a few hormones that do not act as allosteric effectors and therefore whose actions do not depend on specific receptors.
d. specific receptor concentration is never regulated by hormones that do not bind directly to the same receptor class.
e. none of the above
44. Aminoglutethimide is a drug that blocks the conversion of cholesterol to pregnenolone which as you remember is the precursor for sex steroid, glucocorticoid and mineralocorticoid synthesis. Administration of this drug in pharmacologic amounts would result in your patient:
a. a increase in plasma cortisol.
b. a decrease in a plasma estrogen such as estradiol.
c. a decrease in plasma ACTH
d. an increase in plasma aldosterone.
45. In a robbery, a pateint suffered head trauma which resulted in the transection of his pituitary stalk. Which of the following is not likely to occur?
a. a decrease in the production of cortisol
b. a decrease in the release of ACTH by the pituitary
c. a loss of the normal circadian rhythm for ACTH, cortisol, growth hormone and prolactin.
d. gonadal failure.
e. prolactin production will be severely depressed.
46. Neurohormones frequently act at more than one site. Which of the following does not correctly describe dual physiological actions of a neurohormone?
a. TSH possesses the ability to stimulate secretion of both TSH and prolactin.
b. Somatostatin inhibits secretion of growth hormone (GH), TSH and insulin
c. CRH stimulates secretion of ACTH and has actions on the sympathetic nervous system.
d. ADH only has action to affect the kidney tubule cell
47. A 18 year old male patient is referred to you for evaluation of low pituitary function as he failed to grow adequately and mature sexually. His cortisol, thyroxine and GH levels are low as are his circulating levels of TSH and ACTH. You administer TRH and CRH in appropriate multiple doses in the prescribed manner. You note that there is an increase in circulating TSH and ACTH. You conclude:
a. the abnormality resides in peripheral endocrine gland failure (thyroid, adrenal, gonads).
b. the primary abnormality resides in the hypothalamus or its connections to the pituitary
c. the low GH levels must have been due to an abnormality in somatostatin.
d. none of the above
48. In some conditions there is the sustained excess secretion of ADH, as in SIADH (Syndrome of Inappropriate ADH Secretion). In a patient suffering from this condition and allowed free access to water you would expect to find the following:
a. decreased serum osmolality
b. increase in serum sodium chloride concentration
c. increase in mental acuity
d. decrease in intravascular volume
49. Thyroid hormone:
a. is stored predominantly in colloid as L-thyroxine
b. biosynthesis utilizes iodide which is taken into the gland by diffusion and does not require ATP for this process
c. is formed from iodinated tyrosine residues in thyroglobulin that couple.
d. biosynthesis does not occur in the fetal thyroid gland as in the fetus the mother’s thyroxine is sufficient for the normal growth and development of the fetus
50. Hyper-functioning of the thyroid gland in Graves' disease is due to an antibody which interacts with the TSH receptor on the thyroid gland cell. Which of the following findings are expected in Graves' disease?
a. TSH levels are markedly increased to account for the high thyroxine levels found in these patients.
b. iodide uptake as measured by the radioactive iodine uptake test is decreased in these patients as the antibody blocks uptake.
c. TSH levels are low because the high T4 (thyroxine) in Graves disease feeds back on both the hypothalamus and pituitary to decrease TSH production by thyrotropes.
d. weight gain
e. low systolic blood pressure with a relatively higher than expected diastolic pressure giving a narrow pulse pressure
51. Five years after the treatment of the patient described above (Graves' disease) with radioactive iodine treatment, the patient consults you because he feels tired with his usual appetite for life depressed. You suspect that his thyroid gland is now functioning inadequately (hypothyroidism). If this diagnosis is correct you would expect:
a. an elevated blood pressure
b. a slowed pulse rate
c. hyperperistalsis and constant diarrhea
d. both B and C are correct
52. Thyroid hormone:
a. acts on only selected cells. Among these are certain cells of the brain.
b. acts on the thyroid cytoplasmic receptor to activate the cAMP protein kinase cascade
c. makes certain cells more responsive to adrenergic stimulation
d. binds directly to selected regions of the genome
53. A patient with a peptic ulcer has a brisk hemorrhage with a blood loss approaching 1.5 L. Which of the following hormonal changes does not occur to reestablish homeostasis?
a. decreased production of atrial naturetic hormone which has the effect to increase renin production
b. increased secretion of ADH
c. increased secretion of ACTH and cortisol
d. marked decrease in production of renin and therefore aldosterone
e. none of the above
54. A patient develops an adrenocortical tumor in the glomerulosa zone of the adrenal cortex which autonomously produces excessive amounts of aldosterone. This will result in:
a. low blood pressure and rapid pulse
b. atrial naturetic hormone levels will fall and an increase in sodium retention will occur
c. elevated plasma renin will occur and increase aldosterone levels
d. a moderate reduction in serum potassium levels and a metabolic alkalosis
55. Some of the metabolic effects of excess amounts of cortisol on blood sugar are:
a. to decrease blood sugar
b. to increase rate of muscle breakdown with conversion of amino acids to glucose in liver
c. to decrease the levels of gluconeogenic enzymes in the liver
d. to increase collagen and elastic tissue syntheses
56. A Type I diabetic accidentally took 10 times her regular dose of insulin. Which of the following would save her life?
a. a blocker of renal glucose re-absorption
b. an intravenous injection of glucagon
c. a cup of coffee
d. an antiserum to the muscle insulin receptor
57. Glucagon regulates glucose metabolism in the liver by phosphorylating several enzymes resulting in their inhibition. Which of the following are regulated by this mechanism?
a. glucokinase
b. glycogen synthetase
c. 6-phosphofructo-2-kinase
d. glucose-6-phosphatase
58. Mutations in a patient's insulin gene led to an insulin molecule with alanine's instead of lys-62 and arg-63. Which one of the following statements would BEST describe the consequences?
a. the connecting ©-peptide level is low in blood after a meal.
b. exocytosis of granules from the pancreatic b cells is decreased.
c. the patient will require regular insulin injections to properly regulate blood glucose levels.
d. there is a normal to slightly elevated glucose tolerance curve, since there is only a small change in the biological activity of the insulin.
e. there is a down-regulation of the patients insulin receptors.
59. A 2-year old child in a hypoglycemic (low blood glucose) coma is immediately given glucagon intravenously. After 10 min, blood glucose levels have still not returned to normal. Possible explanations are: (A) the patient has no glucose-6-phosphatase activity as a result of heredity; (B) the patient has inherited an inactive mutant of adenylate cyclase; (C) the patient has eaten only protein for several days before the coma; and (D) the patient has inherited a defective insulin receptor gene. Which of the following combinations best characterizes these findings?
a. A and B are true
b. A, B and C are true
c. B, C, and D are true
d. All are true
e. Only A is true
60. Which of the following is not stimulated by insulin?
a. Glucose synthesis
b. Glycogen synthesis
c. Triglyceride synthesis
d. Pyruvate formation from glucose
61. The product of the glucagon gene is:
a. Glucagon + GRPP in pancreatic a cells.
b. Glicentin + GLP-1 + GLP-2 in intestinal L cells
c. Preproglucagon
d. Contains an amino-terminal signal peptide that is cleaved off during processing.
e. All of the above
62. With regard to stimulation of glucagon release from the pancreas in response to amino acids from the diet, which of the following is incorrect?
a. Is not observed in humans.
b. Allows for gluconeogenesis even in the absorptive phase.
c. Is simultaneous with insulin release, only when glucose is low.
d. Is potentiated by a adrenergic stimulation of the a cells.
e. Increases the level of urea in urine, because of increase de-amination by the liver.
63. With regard to acetyl CoA, which of the following is incorrect?
a. Is produced only in the catabolism of carbohydrates.
b. Is the substrate for the Krebs tricarboxylic acid cycle.
c. Produces much more ATP/mole when oxidized than the conversion of glucose to pyruvate.
d. Is produced from free fatty acids by oxidation
e. Can be converted to fatty acids by liver cells
64. Capacitation of spermatozoa occurs:
a. within seminferous tubules.
b. within the epididymis.
c. within the vas deferens.
d. within the efferent ductules.
e. outside the male individual’s body.
65. A patient presents with abnormal sexual development. A thorough examination reveals that the individual has a testis, epididymis, vas deferens, and ejaculatory duct, but they end in a pseudovagina. All external genitalia are female. Based on these observations, the most likely set of sex chromosomes and cause of this condition are:
a. XO, Turner’s syndrome
b. XY, defect in testosterone biosynthesis
c. XY, no androgen receptors
d. XY, a 5-alpha-reductase deficiency
e. XXY, Klinefelter’s syndrome
66. With regard to the hypothalamic-pituitary-testis axis, which statement is FALSE?
a. Testosterone acts on gonadotrophs to decrease secretion of FSH.
b. Dopamine acts on hypothalamic nuclei to decrease secretion of GnRH.
c. Norepinephrine acts on hypothalamic nuclei to increase secretion of GnRH.
d. GnRH acts on gonadatrophs to increase the secretion of both FSH and LH.
e. LH acts on Leydig cells to increase testosterone secretion.
67. Sexual differentiation of the indifferent gonad into a testis requires:
a. human chorionic gonadotropin from the placenta.
b. an intact X-chromosome.
c. an intact long arm of the Y-chromosome.
d. an intact short arm of the Y-chromosome.
e. none of the above.
68. Seman produced by a male that lacks both seminal vesicles will:
a. be relatively more acidic than semen form a normal man.
b. have a lower [Ca2+] than semen from a normal man.
c. have a lower concentration of prostaglandins than normal.
d. both a and b
e. all of the above
69. Peritubular myoid cells:
a. secrete certain molecular components of the basement membrane surrounding seminiferous tubules.
b. secrete protease inhibitors that help maintain the blood-testis barrier.
c. are contractile.
d. all of the above.
e. none of the above.
70. A patient presents with symptoms of hypocalcemic tetany. Blood tests show that in a addition to plasma Ca2+, plasma concentrations of Mg2+, calcitriol, and PTH are all low compared to normal. Plasma phosphate is elevated. Which of the following conditions is consistent with these findings?
a. Vitamin D deficiency due to a lack of adequate sunlight or dietary intake.
b. Vitamin D deficiency due to a problem with receptor activation in target cells.
c. Vitamin D deficiency due to kidney failure.
d. Hypoparathyroidism due to Mg2+ depletion
71. In a patient diagnosed with chief cell adenoma (of the parathyroid gland), which of the following observations would not be expected when compared to normal?
a. a decrease in PO43- absorption in the small intestine
b. a decrease in the plasma [PO43-]
c. an increase in Ca2+ reabsorption in the distal tubule.
d. an increase in osteoclast recruitment and activation.
72. A patient presents with symptoms of hypercalcemia. Lab tests show that in addition to Ca2+, plasma concentrations of PO43- and calcitriol are elevated relative to normal, but PTH is low. Which of the following disorders is consistent with these findings?
a. Primary hyperparathyroidism
b. Secondary hyperparathryoidism
c. Hypoparathryoidism
d. Pseudohypoparathryoidism
e. Excess vitamin D
73. In a patient diagnosed with osteomalcia, which of the following intracellular events would not be expected when compared to normal?
a. an increase in the secretion rate of PTH
b. an increase in the intracellular [calbindin] in intestinal mucosal cells
c. a decrease in the activity of Na+/PO43- cotransporters in the proximal tubule cells
d. an increase in the size and extent of the ruffled border in active osteoclasts.
74. A congenital absence of the gene for what molecule would have an inhibitory effect on osteoclastic resorption?
a. osteonectin
b. osteocalcin
c. osteoclast functional antigen (OFA)
d. transforming growth factor beta
e. alkaline phosphatase
75. As an individual area of bone matrix increases in mineralization,
a. the individual calcium and phosphorus atoms are deposited in a ratio of 5:3.
b. the deposition of calcium and phosphorus is linearly related to time.
c. the water content (percent of wet weight) of the region decreases.
d. the intial mineral precipitates dissolve readily at pH 7.4, thereby restoring plasma calcium and phosphate during episodes of hypocalcemia and hypophosphatemia.
e. all of the above.
76. With regard to the regulation of skeletal remodeling, which of the following likely acts asa coupling factor?
a. the extracellular [Ca2+] in a resorption compartment
b. alkaline phosphatase
c. stromal osteoclast forming activity
d. transforming growth factor beta
e. both c and d.
77. A Ca2+ influx in osteoclasts results in:
a. increased exocytosis.
b. increased activity of carbonic anhydrase.
c. an increase in the size and extent of the ruffled border.
d. decreased exocytosis.
e. a, b, and c are correct.
78. In organ cultures containing viable bone spicules with surface osteoblasts and osteoclasts, treatment with a PTH antagonist would result in:
a. osteoblastic shape changes.
b. an inhibition of collagen type I synthesis
c. increased synthesis of tartrate resistant acid phosphatase
d. an accumulation of lactic acid within osteoclasts.
e. none of the above.
79. Which of the following cell types contain calcitonin receptors?
a. osteoblasts
b. osteoprogenitor cells
c. osteoclasts
d. macrophages
e. both c and d.
80. Pituitary responsiveness to GnRH at the end of the proliferative phase of the menstrual cycle is increased by:
a. FSH
b. LH
c. estradiol
d. inhibin
e. Both FSH and LH
81. A woman is presenting with secondary amenorrhea. An initial evaluation would include all the following measurements except for:
a. Serum Prolactin
b. Serum FSH
c. Height/Weight ratio
d. Serum hCG
e. Serum progesterone
82. Indicate the most likely sequence of tests to be performed on the woman in question #81.
a. Serum FSH, serum prolactin, serum progesterone
b. Serum hCG, height/weight ratio, serum FSH.
c. Serum FSH, Serum testosterone, serum progesterone.
d. Height/weight ratio, serum hCG, serum prolactin.
83. Doctors date pregnancies from the date of the last menstrual period. However the corrrect age of the developing embryo is likely to be:
a. Two weeks less
b. Two weeks more
c. Four weeks less
d. Accurate give or take a few days.
84. Clomiphene citrate is a synthetic antiestrogen which will compete with estrogens at the level of the hypothalamus. It is given in the conditions below except:
a. polycystic ovarian disease
b. ovarian failure
c. anovulatory cycles due to obesity
d. luteal phase insufficiency
85. Which of the following suppresses LH secretion and stimulates milk production?
a. hCG
b. progesterone
c. estrogens
d. prolactin
86. Which of the following steroids are core steroids common to the ovaries, testes and adrenal glands?
a. pregnenolone, progesterone and androgens
b. progesterone, 17-hydroxyprogesterone and androstenedione
c. progesterone, androgens and cortisol.
d. both A and B are correct.
e. none of the above.
87. Which of the following elicits the correct response only when secreted in a pulsatile manner and chronic administration of a synthetic analog can arrest precocious sexual development?
a. GnRH
b. LH
c. estradiol
d. inhibin
88. Which of the following stimulates production of progesterone and estrogens by the corpus luteum?
a. hCG
b. progesterone
c. estrogens
d. prolactin
89. An individual sweats at a rate of 500/hour for three hours and is working in the shade. The ambient temperature is 70 F. There is no breeze and the individual is wearing a shirt and pants. The metabolic rate of the individual during theis three hour period is 400 Kcal/hour. Assume the metabolic rate is proportional to/equivalent to total heat lost per hour in Kcal/hour.
a. The amount of heat lost due to heat conduction and radiative loss is 80Kcal/hour.
b. The metabolic rate is to low to sustain internal body temperature.
c. Cutaneous blood flow is responsible for eliminating via heat conduction and radiative heat loss ~ 33% of the metabolic heat in this case.
d. The amount of heat lost due to water evaporation is less than 200Kcal/hour.
90. With regard to the skin:
a. The stratum basale contains only stem cells for keratinocytes.
b. the permeability characteristics of the skin are embodied for the most part in the stratum corneum.
c. The turn over time for a keratinocyte is ~5 days
d. Melanosomes are only found in Melanocytes.