Download DIRECTIONS: Each of the questions or incomplete statements

DIRECTIONS: Each of the questions or incomplete statements below is followed by five
suggested answers or completions. Select the ONE that is BEST in each case.
1. Parathyroid hormone exerts all the following effects EXCEPT:
(A) Acts directly on osteoclasts to stimulate bone resorption
(B) Acts directly on the kidney to promote reabsorption of calcium
(C) Acts directly to inhibit osteoblast development
(D) Acts directly on the kidney to increase phosphate excretion
(E) Acts indirectly on the intestine to increase absorption of dietary Ca
2. A fall in serum calcium can produce all of the following EXCEPT:
(A) Decreased calcitonin secretion
(B) Increased absorption of calcium in the GI tract
(C) Impaired blood clotting
(D) Cardiac arrhythmias
(E) Muscle weakness
3. The biologically active form of Vitamin D is produced in the
(A) skin
(B) liver
(C) kidney
(D) intestine
(E) bone
4. Two substances (X) and (Y) are injected into separate groups of normal individuals. The
following changes are recorded 4 days post-treatment, relative to a third placebo injected
group (Z).
Substance (X) Substance (Y) Placebo (Z)
change in BMR
+60% +60%
0
Thyroid mass
+20% -15%
0
Which combination below best describes the hormonal nature of X and Y:
(A) X is thyroxine (T4), Y is TSH
(B) X is TRH, Y is TSH
(C) X is tri-iodothyronine (T3), Y is thyroxine (T4)
(D) X is TSH, Y is thyroxine (T4)
(E) X is mono-iodotyrosine (MIT), Y is TRH
5. In Graves disease (the most common form of hyperthyroidism):
(A) Plasma T4 and T3 levels are low
(B) Basal metabolic rate is low
(C) Iodide uptake by thyroid gland is impaired
(D) Plasma TSH levels are high
(E) ) Immunoglobulins stimulate the thyroid TSH-receptor
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6. Administration of tetra-iodothyronine (T4) will produce the following action 2-10 days
post-injection:
(A) induce hypercholesterolemia
(B) decrease hepatic glucose release
(C) inhibit TRH-regulated TSH secretion
(D) induce thyroid T3 synthesis
(E) elevate serum thyroid binding globulin levels
7. In the deficiency of the adrenal enzyme 21-hydroxylasc,
(A) serum glucose levels are elevated
(B) he adrenal gland atrophies
(C) scrum levels of cortisol and aldosterone are decreased
(D) ACTH production is normal
(E) Serum levels of the adrenal androgens are normal
8. In which tissue do glucocorticoids induce an anabolic state?
(A) adipose
(B) muscle
(C) bone
(D) liver
(E) lymphoid tissue
9. Acute elevations in core temperature following the introduction of an exogenous pyrogen
into the hepatic circulation results in the activation of a ncuroimmunological response
which can be blunted following vagotomy. What cell within the liver is proposed to
release an endogenous pyrogen to trigger this response:
(A) The hepatocyte
(B) The Kupfer cell (macrophage)
(C) The sinusoidal endocyte
(D)Hepatic capillary endothelial cells
(D) none of the above
10. An individual exhibiting an elevated core body thermoregulatory set-point during fever
has
(A) an impairment in anterior hypothalamic/ pre-optic area prostaglandin production.
(B) an increase in anterior hypothalamic/ pre-optic area prostaglandin production.
(C) decreased vagal tone
(D) heat stroke
(E) increased gastrointestinal blood flow
11. Dwarfism is known to result from an inactivating mutation in all of the following
EXCEPT:
(A) the Pit l transcription factor
(B) the somatostatin receptor gene
(C) the GHRH receptor gene
(D) the IGF-I gene
(E) the GH receptor gene
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12. The episodic nature of growth hormone secretion is caused by fluctuations in the
secretion of
(A) GHRH.
(B) testosterone.
(C) somatostatin.
(D) insulin.
(E) cortisol.
13. The effects of growth hormone on skeletal growth are mediated by:
(A) insulin
(B) insulin-like growth factor I
(C) cortisol
(D) estradiol
(E) thyroid hormone
14. Growth hormone secretion is stimulated by all of the following EXCEPT:
(A) going to sleep
(B) aging
(C) exercise
(D) testosterone
(E) thyroid hormone
15. During prolonged food deprivation there is a decrease in insulin secretion ana a fall in its
circulating levels. This decrease in insulin results in all of the following EXCEPT:
(A) mobilization of free fatty acids
(B) increased gluconeogenesis
(C) increased phosphoprotein phosphatase activity
(D) decreased muscle glucose utilization
(E) release of glucogenic aminos acids from muscle cells
16. One of the dominant regulators of insulin secretion by pancreatic (β-cells is glucose. The
mechanism of glucose dependent insulin secretion is:
(A) Glycolysis provides ATP to meet the energetic demands of the secretory
apparatus.
(B) Increased ATP causes cell depolarization and Ca2+ influx by inhibiting a K+
channel.
(C) Glucose binds to a receptor that activates the secretory apparatus via second
messengers.
(D) Phosphorylation of glucose by hexokinase causes a fall in cellular ATP resulting
in depolarization and Ca2+ entry.
(E) Elevated ATP levels activate a Ca2+ - pump to increase intracellular Ca2+ and
stimulate secretion.
17. FFA (free fatty acid) oxidation reduces the demand for glucose by which of the following
mechanisms:
(A) oxidation of FFA provides substrates for gluconeogenesis
(B) mobilization of FFA reduces the demand for glucose to provide the backbone for
triglyceride synthesis
(C) tissues such as erythrocyte or lens utilize FFA preferentially over glucose
(D) FFA oxidation elevates cytoplasmic citrate which inhibits phosphofructokinase
(E) FFA oxidation inhibits glucose transport systems
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18. Insulin binding to its receptor activates all of the following EXCEPT:
(A) tyrosine kinasc activity
(B) specific transcription factors
(C) phosphoprotein phosphatase-1
(D) protein kinase B
(E) phosphorylase kinase
19. In untreated diabetes mellitus the failure of the liver to extract glucose is most likely due
to:
(A) decreased glucose permeability
(B) lack of glucokinase
(C) inhibition of phosphofructokinase
(D) depressed plasma glucose concentration
(E) elevated plasma ketone bodies
20. The ketonemia observed in uncontrolled Diabetes mellitus is the result of
(A) excess secretion of adrenal steroids
(B) excessive metabolism of lipids
(C) excessive protein breakdown
(D) gluconcogenesis
(E) impaired renal function
21. All of the following are true about Diabetes mellitus EXCEPT
(A) May result from resistance to the action of insulin
(B) Often associated with obesity
(C) May result from autoimmune reaction
(D) Condition worsened by excessive secretion of adrenal steroids
(E) May result in muscle hypertrophy
22. The growth and development of the dominant ovarian follicle which will extrude the
developing oocyte at ovulation is dependent on which hormone?
(A) Testosterone
(B) Estriol
(C) Cortisol
(D) Estradiol
(E) Thyroid stimulating hormone
23. Of the several hormones synthesized and secreted by the maternal-fetal-placental unit,
which is best suited for the early assessment of a pregnancy?
(A) Androstenedione
(B) Estrone
(C) Human chorionic gonadotropin
(D) Follicle stimulating hormone
(E) Oxytocin
24. During ovarian folliculogenesis the main steroid hormone that is synthesized and secreted
by the growing follicle is
(A) Androstenedione
(B) Progesterone
(C) Cortisol
(D) Estradiol
(E) Cholesterol
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25. All of the following arc effects of estradiol on the reproductive tract EXCEPT:
(A) Thickening of vaginal epithelium
(B) Increased water content of the mucus in the cervix
(C) Progressive increase in progesterone receptors in the endometrium.
(D) Inhibition of muscular contraction of the uterus
(E) increased fallopian tube muscular contractility
26. The menstrual cycle is controlled by the pulsatile release of all of the following hormones
EXCEPT:
(A) Gonadotropin Releasing Hormone (GnRH)
(B) Follicle Stimulating Hormone (FSH)
(C) Luteinizing Hormone (LH)
(D) Estradiol
(E) Oxytocin
27. Implantation of the fertilized ovum occurs in the uterus when the developing embryo is at
the
(A) blastocyst stage (30-200 cells)
(B) morula stage (8 cells)
(C) 2-cell stage
(D) 4-cell stage
(E) stage immediately after fertilization
28. Human chorionic gonadotropin synthesized and secreted by the developing blastocyst has
all of the following characteristics EXCEPT:
(A) Stimulates progesterone synthesis in the corpus luteum
(B) Is a glycoprotein
(C) Consists of two subunits the a and R
(D) It is secreted in early pregnancy
(E) It can be used to assess the development and growth of the fetus in late pregnancy
(six months onwards).
29. Parturition is dependent on all of the following EXCEPT:
(A) Oxytocin hormone secreted by the posterior pituitary
(B) Stretching of the uterine muscle
(C) Ratio of estriol to progesterone produced by placenta
(D) Secretion of prolactin by the maternal pituitary
(E) Signals from the fetus
30. A major function of the corpus luteum is to synthesize and secrete
(A) estrone.
(B) cholesterol.
(C) androstenedione.
(D) progesterone.
(E) testosterone.
31. Which hormone is released in a pulsatile manner by the pulse generator located in the
hvvothalamus?
(A) Gonadotropin Releasing Hormone (GnRH)
(B) Follicle Stimulating Hormone (FSH)
(C) Luteinizing Hormone (LH)
(D) Estradiol
(E) Cortisol
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32. An adult male patient who develops a deficiency in testosterone secretion will exhibit
(A) a decrease in gonadotropin releasing hormone (GnRH)
(B) an increase in sperm production
(C) a decrease in FSH secretion
(D) an increase in LH secretion
(E) hypertrophy of the prostate gland
33. All of the following are properties or functions of the Sertoli cells EXCEPT:
(A) Express receptors for LH
(B) Are required for normal spermatogenesis
(C) secrete a product that inhibits the secretion of FSH by the pituitary
(D) Express receptors for testosterone
(E) Form a "blood-testis barrier" that limits access of blood-borne substances to
developing spermatids
34. An adult male patient who becomes infertile exhibits normal pulsatile secretion of GnRH
yet low levels of FSH and testosterone. The patient most likely has a defect at the level
of the
(A) (Al hypothalamus
(B) pituitary
(C) Leydig cell
(D) Sertoli cell
(E) germ cells
DIRECTIONS: Match each number phrase with the one best lettered answer. Each answer may be used
once, more than once, or not at all.
(A) renin
(B) angiotensinogen
(C) angiotensin I
(D) angiotensin II
(E) atrial natriuretic peptide
35. Binds to receptors on cells of the zona glomerulosa to increase aldosterone secretion
36. Binds to receptors on cells of the zona glomerulosa to decrease aldosterone secretion
--------------------------------------------------------------------------------------------------------------(A) Uncontrolled Diabetes mellitus
(B) Diabetes insipidus
(C) Both
(D) Neither
37. Inability to excrete a concentrated urine
38. Hypertonic plasma
39. Positive free water clearance
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ANSWERS:
1.
2.
3.
4.
5.
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11.
12.
13.
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17.
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22.
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35.
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39.
A
E
C
D
E
C
C
D
B
B
B
C
B
B
C
B
D
E
B
B
E
D
C
D
D
E
A
E
D
D
A
D
A
B
D
E
C
A
B
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