HBY 531 MEDICAL PHYSIOLOGY
LECTURE EXAM 3
2004
Section 1: Answer the following using:
a = increase
b = remain unchanged
c = decrease
1. During the cephalic phase of acid secretion, the Na+ concentration in the stomach will __________. (C)
2. During the gastric phase of acid secretion, the C1- concentration in the stomach will __________. (A)
3. The diameter of the Sphincter of Oddi will __________ in response to secretin. (B)
4. Chief cell secretion of pepsinogen will _________ as secretin levels increase in the blood. (A)
5. Segmentation and peristalsis within the small intestine will ________ in the presence of VIP. (C)
6. For a normal healthy adult, the transport maximum (Tm) for phosphate reabsorption in the kidney will ___________ following a change from a low to a high phosphate diet. (C)
7. Compared to normal, the rate of bone resorption will _______ following a sustained increase in plasma cortisol. (A)
8. Compared to normal, the rate of bone resorption will _________________ following an increase in plasma PTHrp during hypercalemia of malignancy. (A)
9. Compared to normal, the rate of bone resorption will _____________ following the development of hypoparathyroidism. (C)
10. The number of GnRH receptors on gonadotropes will _________ following continuous infusion of GnRH. (C)
11. Plasma testosterone will __________ following continuous infusion of GnRH. (C)
12. Plasma androstenedione levels will _____________ after blocking 17 b-hydroxysteroid dehydrogenase activity. (A)
13. Nitric oxide release during the erection phase of the male sexual response will _________ upon injury to the lumbar splanchnic nerves. (B)
14.
Gonadotropin levels
will_______ following ovulation. (C)
15. With the onset of a primary ovarian failure,
levels of gonadotropins will _______. (A)
16. Placental secretion
of human chorionic gonadotropin
(hCG) will _______ after the
12th gestational week. (C)
Section 2:
For each of the following, choose the single best response.
17. Acid secretion by parietal cells will increase as a result of: (D)
a. blockade of gastrin receptors.
b. increasing prostaglandin levels.
c. cutting the vagus nerve.
d. distension of the stomach
18. Chloride ion flux from crypt cells: (D)
a. is inward if the resting potential is less negative than the chloride equilibrium potential.
b. is inward if the resting potential is more negative than the chloride equilibrium potential.
c. increases as a result of PKA dependent phosphorylation.
d. both a and c.
19. Damage to the 9th cranial nerve (glossopharyngeal): (D)
a. will not affect the oral phase of swallowing.
b. will affect the pharyngeal phase of swallowing.
c. will not affect the esophageal phase of swallowing.
d. all of the above are correct.
20. During receptive relaxation, (C)
a. the pyloric sphincter is relaxed.
b. there is no efferent input via the vagus nerve.
c. chief cell secretion of pepsinogen is ongoing.
d. all of the above are correct.
21. Acid reflux disease: (D)
a. is the result of an incompetent cardio-esophageal sphincter (CES).
b. is the result of a chronically constricted CES.
c. can result in adenocaricinoma of the squamous epithelium of the esophagus.
d. both a and c are correct.
22. Lactose intolerance: (B)
a. is the result of secretory non-inflammatory diarrhea.
b. results in osmotic diarrhea.
c. arises from the lack of the enzyme dextrinase.
d. none of the above is correct.
23. Elevation of intracellular K+ in a columnar absorptive cell of the small intestine: (D)
a. will not affect monosaccharide uptake.
b. will affect fructose uptake.
c. will not affect single amino acid uptake.
d. none of the above is correct.
24. Gastrin levels: (D)
a. will decrease as plasma somatostatin concentrations are elevated.
b. are affected by VIP.
c. are affected by H+ levels in the stomach.
d. all of the above are true.
25. A decrease in blood glucose would be expected to increase: (E)
a. growth hormone.
b. glucagon.
c. insulin.
d. thyroxine.
e. both (a) and (b)
26. A 14-month old girl is brought to her pediatrician, who is informed by her parents of her suffering from frequent early morning fainting spells. This was noticed soon after weaning from breast-feeding and the elimination of the mid-night feeding. She is slightly underweight relative to her peer group, with normal blood pressure, fed blood glucose and insulin levels. Fasting blood glucose levels were found to be 20 to 30 mg/dL (normal 60-120 mg/dL), the results would be consistent with (A)
a. a defect in her pancreatic alpha cells of the islet of Langerhans.
b. a defect in liver glucose-6-phosphate dehydrogenase activity.
c. a defect in her skeletal muscle Insulin Receptor-1 (INS-1) protein.
d. defects in adipose lipolysis and hepatic ketogenesis.
27. Intracellular glucagon action is mediated by activation of protein kinase A and the phosphorylation and inhibition of a number of enzymes, including (D)
a. the skeletal muscle glucose transporter-4 (GLUT-4).
b. liver phosphoenolpyruvate carboxykinase (PEPCK).
c. liver glycogen phosphorylase kinase.
d. liver pyruvate kinase.
28. Proteins with a low-affinity (high Km) for their ligands, allows them to respond to a wider functional range of ligand concentrations. One example is: (A)
a. glucokinase.
b. glucose-6-phosphatase.
c. glucose transporter-1 (GLUT-1).
d. hexokinase.
29. One explanation for the popularity of the Atkins diet is the belief that with a low-carbohydrate, high protein/fat diet, less insulin is secreted from the endocrine pancreas; therefore, there will be less storage and more catabolism, because of (C)
a. the stimulation of thyroxine secretion by high-protein meals.
b. decreased somatostatin secretion with high-fat ingestion.
c. the paradoxical increase in glucagon secretion in the absorptive state.
d. increased glucagon-dependent suppression of insulin activity.
30. Circulating Islet cell antibody (A)
a. is an early characteristic of a type I diabetic (IDDM).
b. can be used to diagnose early stages of type II diabetes (NIDDM).
c. is a common finding in Hashimoto’s thyroiditis
d. is
increased in Acromeg
31. Increased Glucagon AND Insulin secretion after a protein-rich meal low in carbohydrates is metabolically similar to (C)
a. Cushing’s syndrome because excess cortisol leads to increased lipolysis and protein synthesis, but not gluconeogenesis.
b. Grave’s disease because hyperthyroidism leads to increased gluconeogenesis, lipolysis and proteolysis.
c. Acromegaly, because excess Growth Hormone mimics glucagon’s action on carbohydrates and insulin’s action on protein synthesis.
d. an untreated type I diabetic (IDDM) because gluconeogenesis and protein synthesis are both increased.
32. Non-shivering thermogenesis is the major mechanism by which rodents and human newborns raise their body temperature by; (A)
a. increasing the catabolism of fats in brown adipose tissue.
b. changing metabolic rates without increasing O2 consumption.
c. increasing subcutaneous temperature along with O2 consumption
d. activation of b-receptors of brown adipose tissue temperature sensors.
33. The absorptive state of metabolism, following the ingestion of a meal composed of all three major food groups is characterized by (A)
a. the induction of liver glucokinase and the dephosphorylation of pyruvate dehydrogenase
b. the phosphorylation and activation of adipose triglyceride lipase acids and increased ketone synthesis.
c. the translocation of GLUT-2 to liver plasma membrane, resulting in an increase in glucose uptake
d. a
decrease in lipoprotein lipase activity and an increase in circulating free
fatty acids.
34. Sweat is uniquely suited to cool
the adult human body because; (B)
a. adrenergic
stimulation can increase rates of sweat formation to more than 2 liters / hour.
b. cholinergic
stimulation results in increased production of a hypotonic protein-free
solution.
c. apocrine
gland blood supply is very sensitive to small changes in acetyl choline levels
d. b-adrenergic vasodilation of adult skin blood vessels is rapid and quickly reversible.
35. A dexamethasone suppression test is a useful diagnostic tool to distinguish between (C)
a. Cushing’s hypercortisolemia and Addison’s disease.
b. Addison’s disease and autoimmune destruction of adrenal cortex.
c. Pituitary tumors and ecotopic tumors that secrete ACTH.
d. Aldosterone secreting tumors and cortisol secreting tumors.
36. The glucose-dependent synthesis, processing and secretion of insulin requires the expression of several b-islet cell specific genes, including (B)
a. glucose transporter-4 (GLUT-4), glucose-6-phosphatase, and a signal peptidase.
b. a signal peptidase, dibasic converting proteases and an ATP-sensitive K+ channel.
c. glucokinase, the insulin gene itself, and glucose transporter-4 (GLUT-4).
d. a-adrenergic receptors for epinephrine and nor-epinephrine.
37. Hormone receptor regulation maybe considered a critical
factor in endocrine sign
a. they determine which pathway of signal transduction is activated in a particular cell type.
b. their level of expression determines the extent of the endocrine response.
c. they are responsible for the first level of amplification after hormone release.
d. (a) and (c) are true
e. (a), (b) and (c) are true
38. All hypot
a. somatostatin and dopamine
b. pyro Glu-His-Pro
c. corticotrophin and thyrotropin
d. adrenocorticotropic hormone and oxytocin
39. Goiter, a bilateral enlargement of the thyroid gland can sometimes occur in both hypo- and hyperthyroidic states when (A)
a. thyroid stimulating hormone levels are high because of low thyroxine negative feedback or because of a pituitary tumor, respectively.
b. iodine in the diet is too low or thyroid releasing hormone decreases below normal, respectively.
c. either Hashimoto’s thyroiditis or a thyroid tumor are present, respectively.
d. thyroid stimulating hormone levels increase in the presence or absence of thyroid releasing hormone, respectively.
40. An increase in circulating insulin would be expected to increase the transcription of which of the following? (E)
a. lipoprotein lipase
b. phosphoenol carboxykinase (PEPCK)
c. Glucose
Transporter-4 (GLUT-4)
d. Glucokinase
e. (a) and (d)
41. Following the development of primary hyperparathyroidism in a person with otherwise normal kidney function, all of the following would be expected to increase except: (D)
a. urinary hydroxyproline
b. urinary cAMP
c. the filtered load of Ca2+
d. the filtered load of PO43-
e. plasma calcitriol levels
42. With regard to treatments, a patient with vitamin D resistant osteomalacia would benefit most by: (E)
a. being given exogenous calcitriol
b. being given exogenous PTHrp
c. being placed on a PO43- restricted diet
d. being given dietary Ca2+ supplements
e. none of the above
43. In a patient with pseudohypoparathyroidism, the primary problem involves a defect in: (B)
a. the Ca2+ sensor on chief cells of the parathyroid gland
b. PTH receptor activation within target cells
c. calcitriol synthesis
d. calcitriol receptor activation within target cells
e. calcitonin synthesis
44. In a patient with pseudohypoparathyroidism, one would expect plasma: (E)
a. calcitriol levels to be lower than normal
b. PTH legels to be higher than normal
c. Ca2+ levels to be lower than normal
d. PO43- levels to higher than normal
e. all of the above
45. Normal secretion of
estrogens in the ovaries: (E)
a. requires
both FSH and LH.
b. only
requires FSH.
c. involves
the granulosa cells in the active follicles.
d. involves
the thecal cells in the active follicles.
e. a,
c and d.
46. Fertilization of the ovum by the sperm
cell: (D)
a. normally
occurs in the uterus.
b. can
take place several days after ovulation.
c. is
an event in which the egg plays only a passive role.
d. involves
complex molecular interactions between the sperm cell membrane and the zona pellucida.
e. a
and d.
47. Regarding lactation, which of the following
statements is true? (B)
a. Steroid hormones
are not required in order for the mammary gland to achieve functional maturity.
b. Steroid hormones
inhibit milk production and release.
c. There is no
involvement of the brain and all events are due to the hormonal interaction
between the ovaries, the placenta and the mammary gland.
d. Lactation is
triggered after parturition by an increased production of steroid hormones by
the ovaries.
e. The myoepithelial cells that surround the secretory
alveoli in the mammary glands are the target of the pituitary hormone prolactin.
48. A 16 year-old patient seeks medical attention because she has never had a menstrual cycle. Lab tests show normal prolactin levels, normal gonadotropins and presence of bleeding after progesterone withdrawal. Which of the following is (are) possible cause(s) underlying this patient’s amenorrhea? (E)
a. Hypothalamic amenorrhea
b. Pituitary prolactinoma
c. Müllerian agenesis
d. constitutional
delay of puberty
e. a
and d.
49. A 36
year-old patient seeks medical attention because her menstrual cycles have disappeared. Lab tests show high gonadotropin
levels. Bleeding was absent after progesterone withdrawal test, but could be
induced by combined progesterone and estrogen withdrawal. Which of the
following diagnosis is appropriate? (D)
a. Absence of a uterus
b. a pituitary tumor
c. hypothalamic
dysfunction
d. premature menopause
e. none
of the above.
50.
In a 22 year-old patient, who has been amenorrheic for a year, a pregnancy test is negative and prolactin levels are found to be elevated. Which of the
following lab tests would prove useful in diagnosing this patient’s problem?
(E)
a. Measurement of gonadotropin levels
b. MRI scan of the
pituitary
c. Measurement of T4
and TSH
d. Progesterone
withdrawal test
e. b
and c.
51. A
3-year old boy presented with advanced virilization,
including an enlarged penis and well developed pubic hair. Serum testosterone levels were highly
elevated (11 nMol/L), as were serum LH levels and
precocious puberty was diagnosed. What
further treatment would you recommend? (D)
a. hCG stimulation
b. androgen receptor antagonist
c. estrogen receptor antagonist
d. GnRH
agonists
e. none of the above
52. Meiotic cell division must occur in both male and female gamete formation. Which of the following differ between spermatogenesis and oogenesis? (E)
a. the age at which the first meiotic cell division occurs
b. the time interval between the initiation of the first and second meiotic divisions
c. the numbers of gametes produced during an average lifetime
d. the optimal temperature for gamete formation
e. all of the above
53. A
22-year old man presents to a fertility clinic for evaluation. Semen analysis (after 48 hour abstinence)
reveals a lower than normal semen volume, fructose levels are only 50% of normal,
pH = 7.5, and the sperm count is 300 million per mL. Based on this information, this man most
likely: (B)
a. has blockage of one vas
deferens
b. has blockage of one seminal
vesicle
c.
experiences retrograde ejaculation
d. has one cryptorchid
testis
e. has both a and b
Section 3: This
section contains 10 clinical cases. Each
case is followed by several questions. For
each of the following questions, choose the single best response.
Clinical Case
Study 1: A patient enters your ER
and complains of diarrhea which he says is “out of control. It has been
persistent for the last two weeks. He is
not diabetic but does drink heavily. He
complains of developing a “beer gut” over the last 5 months. His blood pressure
is 120/60 and his pulse is 80 beats/minute. The patient also complains that he is very
fatigued. You hold him in the ER for 12
hours and collect stool volumes, which are revealed to be 2L/day. You ask him
about his diet and find out that he likes to eat raw meat and fish. You send him home and insist he hydrate
himself, and reduce or eliminate his intake of raw fish and meat.
54. At this point, based on the above information the most likely diagnosis is that: (A)
a. this patient is suffering from secretory diarrhea.
b. an osmotic diarrhea is the cause.
c. malabsorption is the cause.
d. elevated gastrin or VIP are the most likely candidates causing this man’s diarrhea.
Two days later, the
same patient appears, again complaining of diarrhea, which stool volumes reveal
to be 2L/day. This time you do blood
tests, which indicate that the patient has normal liver function. Analysis of the stool reveals no white cells
and cultures are inconclusive. The
patient tells you that he has recently (over the last month) started a new diet
which includes soft cheese, something he never really had had before (“he loves
the stuff”) . In
addition, for the last two days, he has refrained from eating raw fish and
meat. Further discussion reveals that he
is consuming on average some 2800 calories/day.
He also began using an non-absorbable
artificial sweetener (sorbitol) in an attempt to
reduce his “beer gut” but limits his use to no more than two cups of
coffee/day.
55. Based on this information, the mechanism of this man’s diarrhea most likely involves: (B)
a. the dietary change as the cause of a secretory diarrhea.
b. an osmotic diarrhea because of the lactose content of the cheese.
c. sorbitol as the source of the osmotic diarrhea.
d. both b and c are possible.
Clinical
Case Study 2: A patient presents
with diarrhea. Stool volumes are 0.5
L/day. The inorganic content has been
determined from fluid samples taken from your patient in the ileum and from
fecal material and compared with normal.
The data (mM) are shown in the following Table. The patient always has watery stools.
Na+ K+ C1- HCO3-
Ileum 130 7 70 80
Feces 30 80 20 25
Patient
Na+ K+ C1- HCO3-
Ileum 130 8 90 40
Feces 90 70 40 15
56. The elevated Na+ in the stool of the patient most likely results from: (C)
a. too much mucus being secreted by goblet cells of small and large intestine.
b. increased activity of Na+ transporter on the columnar cells of colon.
c. decreases activity of Na+/H+ exchanger on the columnar cells of colon.
d. increased activity of the Na+/K+ ATPase on the basal surface of the columar cells of the colon.
57. The lowered HCO3- concentration in the ileum and fecal samples of the patient indicate that: (A)
a. the apical C1-/HCO3- exchanger on the columnar absorptive cells of the ileum and colon are dysfunctional.
b. the Na+/glucose co-transporter on the columnar absorptive cells of the ileum is dysfunctional.
c. Carbonic anhydrase within the goblet cells of the colon is not functioning.
d. either b or c.
58. The bile content in the fecal material of the patient: (C)
a. will be increased relative to normal
b. will be decreased relative to normal
c. will be the same as normal
Clinical
Case Study 3: An unconscious patient
with a history of Diabetes mellitus is brought into the emergency room with
irregular breathing, a blood pressure of 110/60, a strong smell of acetone on
his breath, and blood glucose of 260 mg/dL.
59. A possible reason for his fainting is (are) that he is (B)
a. an IDDM (type I) who has accidentally taken too much insulin with his last meal.
b. an
IDDM (type I) who erroneously used s
c. a NIDDM (type II) who has been on a high fat, low carbohydrate diet.
d. a body builder who has taken anabolic steroids and eating only protein supplements for the last 2 days.
60. If the above patient was brought to you on the street without the benefit of clinical chemistry laboratory analyses, and you had immunity from malpractice lawsuits, which of the following emergency treatments would you consider administering until he could be taken to an emergency room? (Assume you have a well stocked doctor bag) (A)
a. an injection of glucagon which should raise his blood glucose, since it is less harmful in the short run to raise his glucose than to lower it.
b. an injection of insulin to lower his blood glucose, this should inhibit the high ketosis (acetone breath), and counteract the acidosis.
c. an injection of somatostatin to block the actions of insulin and glucagon and intestinal glucose absorption.
d. an injection of Miglitol, an a-Glucosidase inhibitor that decreases gastrointestinal absorption of glucose.
Clinical Case
Study 4: A 50-year-old man presents
with enlargement of left anterior neck. He has noted increased appetite over
past month with no weight gain, and more frequent bowel movements over the same
period. He is 5'8" tall and weighs
150 lb. The heart rate is 82 and the blood pressure is 110/76. There is mild
exophthalmia. The thyroid gland is asymmetric to palpation, weighing an
estimated 40g (normal = 15-20g). There is a 3 x 2.5 cm firm nodule in left lobe
of the thyroid. Initial diagnosis is probable hyperthyroidism due to early
Grave’s disease. Subsequent laboratory analyses revealed the following serum
values:
Patient's
value Reference range
Calcium, total 10.6
mg/dl 8.4 - 10.2
Phosphorus 4.8 mg/dl 2.7 - 4.5
Alk
T4 (Total) 15.2 mg/dl 5 - 11.5
T3
(Total) 411 ng/dl 100 - 215
TSH <0.1 mU/ml
0.7 -7.0
Thyroid autoantibodies absent
absent
61. At this point, (B)
a. results confirm hyperthyroidism due to Grave’s disease.
b. results confirm hyperthyroidism due to thyroid tumor since enlargement is not bilateral.
c. results point to a hyperparathyroid tumor that is unilaterally restricting thyroid blood flow.
d. results are consistent with onset of Hashimoto’s thyroiditis.
Five years after
appropriate treatment during which the above patient showed normal serum values
(TSH values were 5.5 mU/ml), he started
to notice a recurrence of his symptoms that were also accompanied by a gradual
loss of muscle tone and muscular atrophy. Blood analysis at this time showed:
Patient's
value Reference range
TSH <0.1 mU/ml 0.7 -7.0
Growth hormone (GH)
<0.1 ng/ml
5-10 ng/ml
(depending on time of day)
62. Possible diagnosis is: (B)
a. he has relapsed and the hyperthyroidism is feedback inhibiting GH release.
b. he
has developed a hypot
c. he has changed his eating habits to carbohydrate-richer meals and less exercise.
d. he was hanging out with the weight lifter in question #14 and was using anabolic steroids.
Clinical Case Study
5: A 6-year-old boy presents with a
history of rapid somatic growth over the last 4 years. He was a full-term
infant born to a 34-year-old healthy mom by normal vaginal delivery after an
uncomplicated gestation. His birth weight was normal and there were no neonatal
problems. Between 9 and 18 months of age, his growth was at the 95th percentile
for his age. His present height and weight were average for 10 year olds. His
genitals appeared larger than those of his peers, and there was fine pubic hair.
He was tall, well-proportioned, and muscular with mild facial acne. His blood
pressure and neurological exam were normal. Testes were small for puberty
stage, and examination showed no abnormal growths.
The following blood
analyses were found:
Patient Reference
Testosterone 172 ng/dl 2 - 12
Lutenizing Hormone (LH), basal 1.7
mU/ml
< 2 (pre-puberty)
FSH, basal <1 mU/ml < 1
ACTH
17-OH-progesterone,
basal 11,690 ng/dl < 100
60 min after ACTH stimulation 22,000 ng/dl < 250
Cortisol, basal 3 mg/dl 5 - 20 (morning)
after ACTH
stimulation 10 mg/dl 2 - 3 x basal
63. These results are consistent with androgen excess and virilization due to (C)
a. probable adrenal cortex hypertrophy and excess adrenal androgen secretion.
b. excess testosterone resulting from an anterior pituitary gonadotroph tumor.
c. a partial block of 21-hydroxylase activity resulting in increased androgens and decreased cortisol.
d. excess testosterone from a testicular hyperplasia, since aldosterone levels are probably normal (normal blood pressure).
64. The above patient was examined by CT and MRI and was found to exhibit bilateral symmetric adrenal hypertrophy, consistent with increased blood ACTH levels.
Treatment consisted of cortisol supplementation, which: (A)
a. inhibits pituitary ACTH secretion, decreasing adrenal androgen production.
b. stimulate endogenous aldosterone and cortisol production.
c. stimulates
secretion of hypot
d. decreases soluble fraction of circulating thyroid hormones.
Clinical Case
Study 6: A 35-year-old man presented
with elevated blood pressure (188/112, seated) at a yearly physical exam.
Previous exams noted blood pressures of 160/94 and 158/92. On questioning, he
admitted episodes about twice a month of apprehension, severe headache,
perspiration, rapid heartbeat, and facial pallor. These episodes had an abrupt
onset and lasted 10-15 minutes. After 30 min the seated blood pressure was
178/110 with a heart rate of 90. The blood pressure after 3 min of standing was
152/94 with a heart rate of 112. The optic fundi
showed moderately narrowed arterioles with no hemorrhages or exudates. Routine
hematology and chemistry studies were within the reference ranges and a chest
film and EKG were essentially normal.
His physician
diagnosed him as suffering from a pheochromocytoma,
and the following values were subsequently found during blood and urinalysis:
Patient
Reference
Plasma Epinephrine 2500 pg/ml 174-624
Plasma Norepinephrine 85 pg/ml 0-114
Urine Norepinephrine
(24 hr) 1800 mg
15 -
80
Rine Epinephrine (24 hr) 100 mg 0 - 20
65. These results are (A)
a. consistent with the physician’s diagnosis and suggest an adrenal pheochromocytoma.
b. consistent with the diagnosis but suggest an extra-adrenal paraganglioma.
c. in
disagreement with the diagnosis and suggest a hypot
d. in
disagreement with the diagnosis, because excess catacholamines
are not symptomatic of pheochromocytomas.
Clinical
Case Study 7: A patient presents
with signs and symptoms of hypocalemia. Subsequent tests confirm a mild to moderate hypocalcemia, but also indicate that while plasma levels of
phosphate are low, plasma levels of both PTH and calcitriol
are elevated.
66. Based on this information, the problem with this patient most likely involves a problem with: (E)
a. the Ca2+ sensor on chief cells of the parathyroid gland
b. PTH secretion
c. the activity of 1a-hydroxylase
d. the activity of 25-hydroxylase
e. calcitriol receptor activation within target cells
67. Left untreated, the rate of bone loss would be expected to _______ compared to normal. (A)
a. increase
b. remain unchanged
c. decrease
68. The condition which best characterizes this patient is: (C)
a. primary hyperparathyroidism
b. type I vitamin D dependent osteomalacia
c. type II vitamin D dependent osteomalacia
d. vitamin D resistant osteomalacia
e. vitamin D intoxication.
Clinical
Case Study 8: A patient presents
with signs and symptoms of hypercalcemia. Further tests confirm that plasma Ca2+ is
elevated along with PO43-, but that PTH is low.
69. At this point, which of the following tests would be most useful in deducing this patient’s problem? (C)
a. measure serum Mg2+
b. measure serum albumin
c. measure serum calcitriol
d. measure serum PTHrp
e. measure urinary cAMP
70. Assuming that the problem is not caused by an exogenous source, which of the following cell types is most likely to be suspect of unregulated secretion? (C)
a. chief cells of the parathyroid gland
b. proximal tubule cells of the kidney in regard to calcitriol secretion
c. immune system cells
d. C cells of the thyroid
e. none of the above
71. Which of the following treatments would be expected to have the greatest benefit in relieving this patient’s symptoms? (D)
a. giving exogenous PTH
b. giving exogenous PTHrp
c. giving vitamin D supplements in the diet
d. giving exogenous calcitonin
e. either a or b
Clinical
Case Study 9: An adult male with a
previous history of delayed puberty presented at clinic because of infertility.
Three adult male relatives in his inbred family also had a history of
infertility. Lab testing shows an elevated serum LH, normal levels of FSH, and
low testosterone. Evaluation of his ejaculate revealed a low sperm count of 11 million/mL.
72. Which of the following tests would be most helpful in diagnosing this patient’s problem? (B)
a. a karyotype analysis
b. a hCG stimulation test
c. pulsatile GnRH infusion
d. estradiol stimulation
e. none of the above be useful
73. Based on the available information, the most likely diagnosis is: (A)
a. hypogonadotropic hypogonadism
b. Klinefelter’s syndrome
c. cryptorchidism
d. testicular torsion
e. none of the above
Clinical
Case Study 10: A 16-year old woman
presents to her physician because of never having had a period. At puberty, normal female secondary sex
characteristics developed, and she appears to be normal. However, upon ultrasound analysis, it is
determined that both Mullerian and Wolffian duct derivatives are absent, and she has a blind
vaginal pouch. Blood tests reveal
elevated testosterone, DHT, and estradiol.
74. Based on this information, a karyotype analysis would most likely reveal: (A)
a. 46, XY
b. 46, XX
c. 47, XXY
d. 47, XXX
e. 45, X
75. Which of the following conditions could account for this patient’s condition? (B)
a. a 5a reductase deficiency
b. an androgen receptor defect
c. Klinefelter’s syndrome
d. a defect in testosterone synthesis
e. Turner’s syndrome