HBY 531 Organ Systems
Final Examination
1999
Section 1: Answer the following using:
A = increase
B = remain the same
C = decrease
1. The rate of emptying of the stomach will _________ if the gastro-gastric reflex is interrupted.
2. The colon-colonic reflex will _________ in the presence of elevated levels of plasma gastrin.
3. The duration of the receptive relaxation reflex will _________ after partial or total vagotomy.
4. The strength of contraction via the myenteric reflex will _________ with partial or total vagotomy.
5. The gallbladder diameter will __________ in the presence of elevated levels of plasma CCK.
6. A pharmacological blockade of calcium channels on smooth muscle cells of the muscularis externa will cause the segmentation rate and peristalic rate to ___________.
7. Removal of the HCO3-/Cl- exchanger on the apical surface of duct cells in the salivary glands will cause the osmolarity of the saliva at basal (i.e., minimal) secretion rates to __________.
8. Removal of the HCO3-/Cl- exchanger on the apical surface of duct cells in the salivary glands will cause the H+ concentration of the saliva to _________.
9. Intestinal secretion arising from crypt cells will ________ upon exposure to VIP on their basolateral surfaces.
10. Late afternoon (i.e., 4PM) serum ACTH levels in a patient diagnosed with hyper-cortisolism will _________.
11. In a patient diagnosed with hyper-cortisolism, their serum ACTH level will ________ after a low dose dexamethasone test.
12. A patient's systolic blood pressure will _______ after taking large doses of cortisol for many weeks.
13. Late afternoon (i.e., 4PM) serum ACTH levels in a patient diagnosed with Cushing's disease will _________.
14. In a patient diagnosed with Cushing's disease, their late afternoon (i.e., 4PM) serum ACTH level will ________ after a high-dose dexamethasone suppression test.
15. DHEA synthesis will __________ after taking metyrapone, a drug used to decrease cortisol secretion by blocking the 11-b hydroxylase step necessary for the synthesis of both cortisol and aldosterone.
16. The level of serum ACTH in the late afternoon will _________ after taking metyrapone.
17. After an injection of dibutryl cyclic AMP (a membrane permeable cAMP analog) into the portal circulation of a patient, the rate of glycogen synthesis will __________.
18. A mutation of a patient's insulin receptor gene resulted in a premature stop codon. In this patient the glucose affinity of muscle GLUT-4 (glucose transporter) will __________.
19. The Vmax of GLUT-2 in muscle and adipose tissue will _________ following an increase in blood insulin levels.
20. Fructose-2,6-bisphosphatase activity will _________ following glucagon infusion into a patient.
21. Assuming no change in net GI absorption of calcium, urinary calcium excretion will __________ during treatment with a loop diuretic such as furosemide.
22. Following an infusion of exogenous PTH into a patient with chronic hypoparathyroidism, urinary phosphate excretion will __________.
23. As the Ca2+ concentration within the resorption compartment (i.e., Howship's lacuna) of an active osteoclast increases from 2mM to 8mM, the number of podosomes will __________.
24. The number of active osteoclasts acting on a patient's skeleton will __________ during lithium therapy.
25. PTH secretion will __________ following infusion of a solution of dibutryl cAMP (a membrane permeable cAMP analog) into the parathyroid gland.
26. Following stimulation of both lumbar splanchnic nerves in the male, arterial vasoconstriction within the penis will __________.
27. Following stimulation of FSH receptors on Sertoli cells, cytosolic aromatase levels _________.
28. Following stimulation of FSH receptors on Sertoli cells, cytosolic pyruvate and lactic acid levels __________.
29. Testosterone secretion from Leydig cells will __________ following an increase in the local concentration of inhibin in the surrounding interstitial fluids.
30. The number of FSH receptors on granulosa cells will _________ after estrogen treatment.
31. Prolactin release will ___________ in response to LH.
32. Gonadotropin secretion in a pregnant female will ___________ after a rise in HCG (human chorionic gonadotropin) levels.
33. Glucose utilization by a pregnant female will _________ after a rise in HCS (human chorionic somatotropin) levels.
Section 2: For each of the following, choose the single best response.
34. The following data has been collected on your patient: Their stools contain blood. Barium imaging reveals no out pocketing indicative of Divericulitis. The patient=s blood pressure was slightly higher than normal. The most likely cause for these symptoms is:
a. Crohn's Disease.
b. inflammatory secretory diarrhea.
c. ulcerative Colitis.
d. spastic colon.
e. none of the above.
35. Your patient has a gastric ulcer. Application of histamine antagonists has no affect. Bacterial infection is not a possibility. Blockade of the K+/H+ ATPase on the apical surface of the parietal cells does relieve the symptoms. What is the most likely reason?
a. Tumors of the secretin secreting endocrine cells of the duodenum are overproducing secretin.
b. CCK plasma levels are too low.
c. Tumors of the gastrin secreting endocrine cells of the stomach are overproducing gastrin.
d. Tumors of the chief cells are the cause of the ulcer.
e. a and b are correct.
36. The majority of pancreatic enzymes are secreted in an inactive form EXCEPT for:
a. hydrolase.
b. phospholipase.
c. ribonuclease and Nulceotidease.
d. cholestrol esterase.
e. a, c, and d are all correct.
37. Gastrin can cause:
a. increased acid secretion by parietal cells.
b. increased motility (more contractions) to occur in the pyloric stomach.
c. the gallbladder to relax.
d. increased motility (more contractions) to occur in the colon.
e. All of the above except c
38. Pancreatic acinar cells:
a. secrete the enzyme amylase.
b. increase their secretion rate in response to CCK and secretin.
c. decrease their secretion rate in response to gastrin.
d. transport no inorganic ions from basolateral surface to lumenal surface
e. both a and b
39. During the absorptive state:
a. HDLs and VLDLs arise solely from lipid absorption in the columnar absorptive cells in the small intestine.
b. amino acids can be a source of ATP in the liver.
c. glucose can be converted into lipids in Adipose cells.
d. most absorbed lipids bypass the liver because they leave the GI tract via lymphatic vessels.
e. All of the above except a
40. The resting potential of a crypt cell in the small intestine is -48 mV. The intracellular Cl- concentration is 20 mM and the lumenal concentration is 140 mM. ECl = 57 log ([Cl]i/[Cl]o).
a. The equilibrium potential for Cl- is -20 mV.
b. The net flux of Cl- is outward
c. The net flux of Cl- in inward
d. The net flux of Cl- is 0.
41. Excessive dietary intake of MgCl2 could result in:
a. Constipation
b. Secretory diarrhea
c. Osmotic Diarrhea
d. elevated levels of Mg2+ in the blood.
e. None of the above is true.
The above figure shows data collected from a patient where stomach pH (filled circles), stomach volume (open squares), small intestine volume (open diamonds), and colon volume (open circles) were monitored using a variety of methods. The arrow indicates when the patient ingested a meal consisting of 1000 ml of Gatorade, an isosmotic drink containing sugars and inorganic components, and 100 grams of meat. Previously the patient had not ingested any food or fluid for 24 hours.
Refer to figure for questions 42-45:
42. The total number of moles of H+ which are free in solution at 2 hours is:
a. 100 mMoles
b. 10 mMoles
c. 20 mMoles
d. 1 mMole
e. none of the above is true.
43. The decrease in both small intestine and colon volume after the first hour arises from:
a. the gastroileal reflex.
b. defecation.
c. the gastro-gastric reflex and the colon-colonic reflex respectively.
d. the migrating myoelectric complex (MMC).
e. a and b are true
44. The total fluid secreted into or by the small intestine is approximately:
a. 700 mL
b. 1500 mL
c. 0 mL
d. 250 mL
45. Based on the data shown, one would predict that the patient is suffering from which of the following?
a. Secretory diarrhea
b. Osmotic diarrhea
c. Partial blockade of the common bile duct
d. Constipation
e. b and c are possible
46. Our cells and body fluids are hyperosmotic to the water of a swimming pool. We do not swell and pop when we go for a swim because:
a. extracellular glycolipids effectively block the diffusion of water.
b. water that enters through skin readily diffuses out.
c. osmotic pressure drives the water out.
d. water is immediately transported to kndney.
e. epidermal continuity works hand in hand with acid mantle to prevent water coming in.
47. The cessation of thermoregulatory mechanisms may lead to which of the following?
a. Heat exhaustion.
b. Fever.
c. Heat stroke.
d. Coma.
e. Shivering.
48. A male patient was in an auto accident in which he suffered significant head injury. His injury resulted in the transection of his pituitary stalk. At about 1 week after the injury which of the following is likely to occur?
a. A marked increase in the production of cortisol leading to Cushing's Syndrome
b. Maintenance of the normal circadian rhythm for ACTH and Growth Hormone
c. An increase in the release of Thyroid Stimulating Hormone (TSH) by the anterior pituitary in response to cold
d. Prolactin secretion by the anterior pituitary will be abnormal and increased.
49. Which of the following is true regarding L-Thyroxine (T4)?
a. It circulates in the blood mainly as the free form and unbound to protein such as TBG or albumin as it is water soluble.
b. It binds to the TSH receptor on the plasma membrane of the end effector tissue (liver) eliciting the hormone directed responses.
c. It (T4) carries iodide through the plasma membrane where iodide affects cell metabolism.
d. It is the precursor for T3 which is formed from T4 within the target cell by a specific enzyme.
50. Grave's disease is caused by an auto-antibody that interacts with the thyroid gland cell initially producing hyper-functioning of the gland. Which of the following findings is NOT expected in patients with Graves Disease?
a. An increased systolic pressure with a relatively low diastolic pressure
b. Warm wet skin with a dislike for warm temperatures.
c. Abnormal eye stare, puffy areas about the eyes and a lid lag.
d. Increased TSH blood levels with a marked circadian rhythm.
51. A patient suffers from Addison's Disease. In this case it is the auto immune mediated destruction of the adrenal cortex that produced the disease. In this patient you would expect:
a. a low level of ACTH and growth hormone in the blood during the sleep period.
b. very low levels of epinephrine in the blood.
c. a high level of ACTH in the blood in the afternoon.
d. an abnormally high blood pressure and high blood sugar after exercise.
52. A patient is treated with pharmacologic doses of dexamethasone (a potent glucocorticoid) for the auto immune disease systemic Lupus Erythematosis. The disease is well controlled and the patient is in a full remission. In this patient you would expect:
a. ACTH blood levels to be high in the 8 AM blood sample.
b. cortisol blood levels to be very low through the 24 h period.
c. TSH blood levels to be high in the 8 AM blood sample.
d. the patient is able to heal skin lacerations and resist bacterial infection more than would be expected in the normal individual.
53. The Adrenogenital Syndrome is the term given to a group of diseases in which there are congenital enzyme deficiences in pathways of adrenocortical hormone synthesis. A deficiency of the 21-hydroxylase enzyme which converts progesterone to 11-deoxycorticosterone (DOC) and 17-OH-progesterone to 11-deoxycortisol limits the production of cortisol and aldosterone. In such a patient during embryogenesis or during early childhood with a deficiency of the 21-hydroxylase enzyme you might find:
a. high levels of circulating aldosterone and a low level of blood K+.
b. atrophy of the zona fasciculata and reticularis of the adrenal cortex.
c. abnormal masculinization of the female child.
d. high levels of cortisol in the 8 AM blood sample.
54. Many hormones bind to blood proteins. This binding serves several purposes and has consequences. Among these are that:
a. binding to protein makes the hormone more readily accessible to the interior of the target cell as there are specific plasma membrane transporters for the hormone protein complex.
b. binding to protein makes the hormone more easily excreted in the urine.
c. it is usually not neccessary to measure "free hormone" in the blood as all the action is in the complex.
d. binding, in some cases, provides a "reservoir" of hormone and as such can serve to "buffer" acute changes in hormone secretion by the gland.
55. Which of the following is an effect of growth hormone?
a. It desensitizes fat cells to the effect of epinephrine in terms of increasing the release of free fatty acids.
b. It increases the sensitivity of muscle to insulin.
c. It increases the production of somatomedins by tissues such as liver.
d. It allows the growth of long bones in a linear fashion even in the adult.
56. A man who has smoked for 22 years now has developed a bronchogenic (lung) carcinoma. This tumor also produces ACTH (ectopic production). In addition to the ravages produced by the carcinoma, this patient might also suffer from:
a. bilateral adrenal hyperplasia with signs and symptoms of Cushing's Syndrome.
b. increased blood aldosterone levels with low blood potassium and high blood pressure.
c. low blood sugar and the inability to maintain blood pressure.
d. high prolactin levels with some minimal milk production.
57. A 45-year old, slightly over weight male patient complains of frequent urination, and thirst. A subsequent glucose tolerance test showed elevated fasting and two hour blood glucose levels. The patient can be tentatively diagnosed as a(n):
a. IDDM if connecting (C-) peptide to insulin ratio in the blood are low.
b. IDDM if immunoreactive insulin levels in the blood are elevated after 2 hr.
c. NIDDM if no Islet Cell Antibodies (ICA) are detected in the blood.
d. NIDDM if immunoreactive insulin levels in the blood are elevated after 2 hr.
58. The addition of a radioactively-tagged cholesterol to a normal rat diet would be expected
a. to appear in chylomicrons and then in adipose after apoprotein C2 removal by HDL.
b. to appear in chylomicrons and then in liver after hydrolysis of core triglycerides.
c. to appear in LDL particles after clearance of chylomicron remnants by the liver.
d. to appear in VLDL particles then in liver after hydrolysis of core triglycerides.
59. You've just eaten an "all beef patty" for breakfast with literally no carbohydrate
a. your blood immunoreactive insulin levels should increase, only if you had not eaten carbohydrates for the last 8 hr.
b. your blood immunoreactive insulin and glucagon should both increase unless you are an IDDM.
c. your blood immunoreactive glucagon levels should increase unless you are have a mutation in your glucagon mRNA sequence.
d. your blood glucose levels will remain relatively constant because muscle and other tissues adapt to the use of ketone bodies for energy.
60. The transcription of several genes is enhanced by an increase in intracellular cAMP levels, this is mediated by the phosphorylation of the cyclic AMP Regulatory Binding Protein (CREB). Which of the following are subject to this form of regulation?
a. Fructose-2,6-bisphosphatase
b. Glucokinase
c. PEPCK
d. Pyruvate kinase
61. 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,
(D) The patient has inherited a defective insulin receptor gene.
a. A and B are true.
b. B and C are true.
c. C and D are true.
d. A and C are true.
e. Only A is true.
62. Select the one FALSE statement in the following.
a. Ketone bodies are water-soluble.
b. Pancreatic somatostatin inhibits insulin as well as glucagon release.
c. Human red blood cells rely exclusively on glycolysis for energy, because they have no mitochondria.
d. The connecting ©-peptide of insulin is cleared from circulation at about the same rate as insulin.
63. A culture of isolated islets of Langerhans were incubated with high levels of glucose in the culture medium. Which of the following is true?
a. Insulin secretion is increased only if K+ is in the culture medium.
b. Insulin secretion is increased only if Ca2+ is in the culture medium.
c. Insulin secretion is increased only if intracellular cAMP levels are reduced.
d. Insulin secretion is increased only if basic amino acids are also present in the culture medium.
64. An increase in urea secretion into the urine is observed in untreated IDDM as a result of
a. increased muscle catabolism of endogenous lipid stores.
b. increased transamination of amino acids and urea synthesis in liver.
c. decreased glucose utilization by tissues due to the absence of insulin.
d. decreased VLDL clearance by extrahepatic.
65. Which of he following conditions is consistent with a laboratory finding of mild hypocalcemia, extreme hypophosphatemia, elevated PTH, and elevated calcitriol?
a. Type II vitamin D dependent osteomalacia
b. Vitamin D resistant osteomalacia
c. Primary hyperparathyroidism
d. Secondary hyperparathyroidism associated with renal failure
e. Vitamin D intoxication
66. Which of the following conditions is consistent with a laboratory finding of hypercalcemia, hypophospatemia, elevated calcitriol, but low PTH levels?
a. Primary hyperparathyroidism
b. Vitamin D resistant osteomalacia
c. Vitamin D intoxication
d. Hypercalcemia of malignancy
e. Hypoparathryoidism
67. Familial benign hypocalciuric hypercalcemia is an inherited trait involving a mutation of:
a. vitamin D receptors.
b. PTH receptors.
c. chief cell Ca2+ receptors.
d. the Ca2+ ATPase.
e. the 1a hyroxylase.
68. Of the following conditions, all involve sustained stimulation of the 1a hydroxylase activity within proximal tubule cells EXCEPT:
a. primary hyperparathyroidism.
b. vitamin D resistant osteomalacia.
c. hypercalcemia of malignancy.
d. pseudohypoparathyroidism.
e. lithium therapy.
69. Of the following conditions, all involve chronically enhanced bone resorption EXCEPT:
a. vitamin D resistant osteomalacia.
b. type I vitamin D dependent osteomalacia.
c. vitamin D intoxication.
d. hypercalcemia of malignancy.
e. hypoparathyroidism.
70. The renal response to a sudden increase in dietary phosphate involves:
a. an increase in Na+ dependent PO43- transport in proximal tubule cells.
b. an increase in cAMP dependent Ca2+ entry at the luminal surface of distal tubule cells.
c. an increase in the filtered load of calcium.
d. a decrease in the filtered load of phosphate.
e. both b and c.
71. Gene transcription of which of the following osteoblast secretory products is decreased following activation of vitamin D receptors?
a. Osteocalcin
b. Osteonectin
c. Collagen type I
d. Alkaline phosphatase
e. None of the above
72. Which of the following hormones exerts an inhibitory influence on 1a hydroxylase activity within proximal tubule cells?
a. Calcitriol
b. PTH
c. Prolactin
d. Growth hormone
e. None of the above
73. Which of the following factors might contribute to acute hypocalcemia?
a. A drop in the serum albumin concentration
b. Infusion of a large volume of blood in which citrate is used as anticoagulant
c. A decrease in plasma pH
d. A drop in plasma phosphate
e. Both a and b
74. A congenital absence of the gene for what molecule would have an inhibitory effect on osteoclastic resorption?
a. Alkaline phosphatase
b. Osteocalcin
c. Carbonic anhydrase
d. Osteopontin
75. In a condition known as testicular feminization, individuals possess testes, no internal genitalia, and feminine external genitalia. This condition arises from a congenital defect involving the gene expression of which of the following?
a. Testis determining factor (TDF)
b. Anti-mullerian hormone (AMH)
c. Androgen receptors
d. 5a reductase
e. Aromatase
76. An individual with Klinefelter's syndrome (karyotype: 47, XXY) would be expected to exhibit:
a. a normal sperm count.
b. Mullerian duct differentiation.
c. elevated testosterone levels.
d. elevated FSH levels.
e. both c and d.
77. Interruption of the pelvic splanchnic nerves in the male will affect which of the following processes?
a. The transmission of sensory stimuli arising from the glans penis
b. Nitric oxide release in the vicinity of penile helicine arteries
c. Bulbourethral gland secretion
d. Vasoconstriction of penile arteries
e. both b and c
78. Lab tests from a male patient suspected of infertility reveal oligospermia and elevated plasma levels of LH and FSH. By contrast plasma testosterone levels are low. Which of the following conditions is consistent with these findings?
a. A pituitary tumor involving unregulated secretion of prolactin
b. A pituitary tumor involving unregulated secretion of gonadotropins
c. Hypersecretion of GnRH by hypothalamic neurons
d. A defect in androgen synthesis
e. Both b and c
79. For a second male patient suspected of infertility, blood tests show normal plasma levels of LH, FSH, and testosterone. Results from the semen analysis reveal oligospermia, but semen volume, composition, and pH are normal. Which of the following conditions is consistent with these findings?
a. Retrograde ejaculation
b. Obstruction of the ejaculatory ducts
c. Congenital absence of the seminal vesicles
d. Blockage of large numbers of prostatic glands
e. Obstruction of the vas deferens
80. Infusion of exogenous testosterone to a normal fertile man will:
a. decrease the rate of mitotic division by spermatogonia.
b. increase GnRH secretion by hypothalamic neurons.
c. stimulate gene expression of the b -subunit within gonadotrophs.
d. increase the rate of synthesis of sex steroid binding globulin (SSBG).
e. do all of the above.
81. During the process of fertilization, the structure that is responsible for the prevention of polyploidy (i.e., n > 46 chromosomes) is the:
a. corona radiata
b. zona pellucida
c. oocyte plasma membrane
d. acrosome reaction
e. cumulus oophrous
82. Fallopian tube formation is dependent on the presence of:
a. chorionic gonadotropin.
b. estrogens.
c. progesterone.
d. anti-Mullerian hormone (AMH).
e. none of the above.
83. The establishment of the menstrual cycle is dependent on:
a. pulsatile secretion of Gonadotropin-releasing hormone.
b. an endometrium responsive to sex steroids.
c. progesterone secretion by the corpus luteum.
d. an open and contracting oviduct.
e. estrogen secretion by the developing follicle.
84. A 24-year-old female with previously normal menstruation begins to have irregular menstruation. A pregnancy test is negative. She is undertaking a major career change and states that she wants a quick resolution to her problem. Which lab study would be the most approapriate?
a. Measurement of prolactin levels
b. Measurement of Thyroid-stimulating hormone (TSH)
c. Measurement of FSH levels
d. Progesterone challenge
85. What test is not diagnostic of a defect in corpus luteum function?
a. Measurement of body temperature
b. Endometrial biopsy and histological dating
c. Measurement of serum progesterone
d. Determination of the length of the luteal phase
e. Measurement of serum estrogen
86. Which of the following is not indicative of ovulation?
a. A rise in body temperature
b. Pregnancy
c. Progesterone levels above 6.5 ng/ml
d. Secretory endometrium
e. Menstruation
87. Which of the following is not characteristic of the follicular phase of the menstrual cycle?
a. Peak estrogen levels
b. Ovulation
c. Peak progesterone levels
d. High FSH levels
88. Which statement about the two cell theory of estrogen production is FALSE?
a. Luteinizing hormone stimulates Theca cells to produce androgens.
b. In a graffian follicle, androgens diffuse through microcapillaries to the granulosa cells where they are aromatized to produce estrogens.
c. Granulosa cells from the late follicular phase respond to LH by increasing progesterone production.
d. Granulosa cells from the late follicular phase respond to FSH by increasing conversion of androgens to estrogens.
e. LH receptors are only present on theca cells in a secondary follicle.
89. Which statement accurately describes both estrogen and progesterone?
a. They decrease the incidence of heart disease in postmenopausal women.
b. They are synthesized from cholesterol in the ovary and acting exclusively on the endometrium.
c. They peak during the first trimester of pregnancy.
d. They increase growth and differentiation of mammary tissues and initiate milk production.
90. Which statement is FALSE?
a. The FSH to LH ratio is highest at the end of menses during the menstrual cycle.
b. The dominant follicle secretes enough estradiol to inhibit cohort follicles and to condition the GnRH-gonadotropin axis for a surge in LH.
c. Abrupt loss of estradiol and estrogen at the end of the luteal phase causes contraction of uterine muscles and arteries producing ischemia and necrosis.
d. Increase in progesterone after ovulation increases mitotic activity of the proliferating endometrium and enhances glandular secretions.
e. All statements are correct.