BLOCK 2: ENDOCRINE II QUIZ GMS
6419 QUESTIONS WITH VERIFIED
ANSWERS 2026-2027
Situation # 1 - correct answer-
A man has renal failure and is maintained on chronic hemodialysis until a donor kidney can be found.
1. This man exhibits increased circulating levels of PTH. Why?
A. Because of increased excretion of phosphate by the kidneys, leading to lowered circulating PO4-
B. Because of a lack of conversion of 25-(OH)D3 to 1,25-(OH)2D3 in the liver
C. Because of increased absorption of calcium and phosphate from the intestine into the blood, and incr
eased circulating Ca2+
D. Because of a lackKof 1,25-
(OH)2D3 production by the kidneys, and therefore no inhibitory action of this Vitamin D metabolite on P
TH synthesis by the Chief Cells - correct answer-D
renal failure results in the inability to excrete PO4- so phosphate levels are raised -
> resulting in complexed Ca++ and lowered plasma calcium
& high levels of PO4-
inhibit calcitriol metabolism, causing the inactive metabolite of VitD (24,25(OH)2D3 to be formed instea
d
calcitriol has a (-) feedback mechanism at the parathyroid -
it switches off PTH synthesis and increases CaSR synthesis in the chief cells
w/o the (-) feedback mechanism PTH syn/sec goes unchecked -> increased circulating PTH
2. Assuming that this person is receiving good medical care, which of the following would be an essentia
l supplement to his hemodialysis.
A. Daily injections of 25-(OH) D3
, B. Plenty of exposure to sunlight
C. ChronicKadministration of rhPTH (Forteo)
D. Administration of 1, 25-(OH)2 D3
E. A diet rich in Vitamin D3 - correct answer-D
administration of calcitriol [1,25 (OH)2D3]
3. Injection of calcitonin into thisKman during his maintenance period on
hemodialysis would cause:
A. A large excretion of calcium in the urine
B. Inhibition of bone breakdown
C. Increased synthesis of 25-(OH) D3
D. Increased production of 1, 25-(OH)2 D3
E. A large increase in bone resorption - correct answer-calcitonin -
tones down calcium in blood inhibits bone resorption & stimulates Os.b
B
1. Growth hormone has several direct and indirect actions. Which one is indirect action?
a. Increases in collagen synthesis
b. Decreased glucose uptake
c. Reduced lipogenesis
d. Reduced protein synthesis
e. None of the above - correct answer-a
collagen synthesis is mediated by IGF
6419 QUESTIONS WITH VERIFIED
ANSWERS 2026-2027
Situation # 1 - correct answer-
A man has renal failure and is maintained on chronic hemodialysis until a donor kidney can be found.
1. This man exhibits increased circulating levels of PTH. Why?
A. Because of increased excretion of phosphate by the kidneys, leading to lowered circulating PO4-
B. Because of a lack of conversion of 25-(OH)D3 to 1,25-(OH)2D3 in the liver
C. Because of increased absorption of calcium and phosphate from the intestine into the blood, and incr
eased circulating Ca2+
D. Because of a lackKof 1,25-
(OH)2D3 production by the kidneys, and therefore no inhibitory action of this Vitamin D metabolite on P
TH synthesis by the Chief Cells - correct answer-D
renal failure results in the inability to excrete PO4- so phosphate levels are raised -
> resulting in complexed Ca++ and lowered plasma calcium
& high levels of PO4-
inhibit calcitriol metabolism, causing the inactive metabolite of VitD (24,25(OH)2D3 to be formed instea
d
calcitriol has a (-) feedback mechanism at the parathyroid -
it switches off PTH synthesis and increases CaSR synthesis in the chief cells
w/o the (-) feedback mechanism PTH syn/sec goes unchecked -> increased circulating PTH
2. Assuming that this person is receiving good medical care, which of the following would be an essentia
l supplement to his hemodialysis.
A. Daily injections of 25-(OH) D3
, B. Plenty of exposure to sunlight
C. ChronicKadministration of rhPTH (Forteo)
D. Administration of 1, 25-(OH)2 D3
E. A diet rich in Vitamin D3 - correct answer-D
administration of calcitriol [1,25 (OH)2D3]
3. Injection of calcitonin into thisKman during his maintenance period on
hemodialysis would cause:
A. A large excretion of calcium in the urine
B. Inhibition of bone breakdown
C. Increased synthesis of 25-(OH) D3
D. Increased production of 1, 25-(OH)2 D3
E. A large increase in bone resorption - correct answer-calcitonin -
tones down calcium in blood inhibits bone resorption & stimulates Os.b
B
1. Growth hormone has several direct and indirect actions. Which one is indirect action?
a. Increases in collagen synthesis
b. Decreased glucose uptake
c. Reduced lipogenesis
d. Reduced protein synthesis
e. None of the above - correct answer-a
collagen synthesis is mediated by IGF
