PHYSIOLOGY – ENDOCRINE SYSTEM
1.
Which of the following statement is TRUE?
A.
T3 is converted to T4 in the periphery
B.
T4 is more metabolically active than T3
C.
Thyroglobulin is synthesized in thyroid cells
D.
T3 & T4 are synthesized in thyroid cells
E.
All of the above
2.
Iodine is mainly excreted in:
A.
Bile
B.
Urine
C.
Sweat
D.
Expired air
E.
All of the above
3.
Which enzyme is used to catalyze formation of T3 & T4?
A.
Tyrosine peroxidase
B.
Thyroglobulin peroxidase
C.
Iodotyroiside deiodinase
D.
All of the above
E.
None of the above
4.
Which of the following is FALSE regarding circulating thyroid hormone?
A.
Most circulating T4 is bound to Thyroid binding globulin (TBG)
B.
Most circulating T3 is bound to albumin
C.
Bound T3 & T4 are physiologically active
D.
TBG has higher affinity for binding T3 &T4 than does albumin
E.
T3 has shorter half life than T4
5.
Which of the following is TRUE regarding drug effects on thyroid hormones?
A.
Oral contraceptive pill increases concentration of thyroid binding globulin & so reduces free T3 & T4.
B.
Prednisolone reduces concentration of thyroid binding globulin & so increases free
T3 & T4.
C.
Phenytoin & salicylates inhibits T3 & T4 binding.
D.
Major tranquillisers increase the concentration of thyroid binding globulin & so increase total T3 & T4 but free T3 & T4 levels are normal.
E.
All of the above
6.
Which of the following regarding circulating T3 is FALSE?
A.
87% are from peripheral conversion of T4.
B.
It has 3-5x more rapid action on end organs than T4.
C.
Conversion of T4 to T3 takes place in pituitary, liver & kidney
D.
1/3 of circulating T4 is converted into T3
E.
All of the above
PHYSIOLOGY – ENDOCRINE SYSTEM - MCQ 1

7.
Peripheral conversion of T4 to T3 is reduced in:
A.
major burns & trauma
B.
Selenium deficiency
C.
Cirrhosis & renal failure
D.
Fever
E.
All of the above
8.
Thyroid hormone increases oxygen consumption of:
A.
Brain
B.
Gonads
C.
Heart
D.
Anterior pituitary
E.
Spleen
9.
Which of the following regarding action of thyroid hormone is FALSE?
A.
Directly positive inotropic & chronotropic action on the heart.
B.
Promotes catabolism
C.
Reduces total peripheral resistence
D.
Increase sensitivity of adrenaline receptors to catecholamines
E.
Reduces cholesterol by increasing LDL receptors in liver
10.
Which of the following regarding Thyroid stimulating hormone (TSH) is FALSE?
A.
Secretion peaks at midnight & declines during the day
B.
T4 is responsible for feedback inhibition of TSH
C.
TSH receptors can be stimulated by
 hCG due to its homology to TSH.
D.
Dopamine, glucocorticoid & somatostatin inhibit it.
E.
Together with IGFI & EGF, TSH has trophic effect on thyroid gland.
11.
Effect of TSH on thyroid gland does NOT include:
A.
Increased iodide binding
B.
Increased thyroid blood flow
C.
Increased T3 & T4 synthesis
D.
Increased thyroglobulin synthesis
E.
Increased colloid endocytosis
12.
Which of the following regarding effect of hypothyroidism is FALSE?
A.
Hypothyroid fetus fails to develop in utero.
B.
Myxodema is due to accumulation of skin protein & water.
C.
Mental disturbance occurs
D.
Slow relaxation phase of ankle stretch reflex
E.
Husky & slow voice.
PHYSIOLOGY – ENDOCRINE SYSTEM - MCQ 2

13.
Which of the following pairing of thyroid disease & its pathology is TRUE?
A.
Grave’s disease – increased TSH receptor stimulating antibodies
B.
Hashimoto’s thyroiditis – increased antithyroglobulin antibodies
C.
Solitary toxic adenoma – adenoma with increases thyroid hormone secretion irrespective of TSH level.
D.
TSH secreting pituitary tumor – increased circulating TSH & thyroid hormone
E.
All of the above
14.
Which of the following regarding iodide is FALSE?
A.
Large doses can stimulate thyroid gland to produce T3 & T4
B.
Reduced thyroid gland response to TSH
C.
Inhibits proteolysis of thyroglobulin
D.
All of the above
E.
None of the above
15.
Which of the following regarding insulin is FALSE?
A.
It is released with equimolar amount of C peptide
B.
Its half life is about 5 minutes
C.
Receptors are present on insulin sensitive cells such as liver & muscle
D.
80% is degraded in liver & kidney
E.
None of the above
16.
Insulin causes increased entry of the following substance into cells EXCEPT:
A.
Potassium
B.
Sodium
C.
Glucose
D.
Amino acids
E.
None of the above
17.
Which of the following is NOT an action of insulin?
A.
Increased glycerol phosphate synthesis
B.
Stimulates lipoprotein lipase
C.
Increased ketone uptake into muscle cells
D.
Stimulates gluconeogenesis
E.
All of the above
18.
Which of the following regarding insulin receptor is FALSE?
A.
It is a steroid receptor
B.
It is a tetramer with 2

& 2

glycoprotein subunits linked by disulfide bonds
C.
It is similar in structure to IGFI receptors
D.
It is endocytosed upon insulin binding & degraded
E.
Its number increases in starvation
PHYSIOLOGY – ENDOCRINE SYSTEM - MCQ 3

19.
Insulin receptors increase in number with:
A.
Obesity
B.
Acromegaly
C.
Exogenous corticosteroids
D.
Adrenal insufficiency
E.
All of the above
20.
In diabetes mellitus, there is:
A.

glucose entry into peripheral tissues
B.

hepatic gluconeogenesis
C.

amino acid uptake into the cell
D.

lipolysis
E.
All of the above
21.
Which of the following regarding diabetes mellitus is INCORRECT?
A.
Glucose uptake by neurones & red cells is normal
B.
Glucose resorption from urine is reduced
C.
Glycogenolysis is stimulated
D.
Hepatic glucose output is facilitated by glucagon & cortisol
E.
All of the above
22.
Uncontrolled diabetes mellitus does NOT:
A.

serum osmolality
B.
 urine sodium & potassium loss
C.
negative nitrogen balance
D.

circulating lipids
E.

circulating lactate
23.
Autonomic symptoms in hypoglycemia occurs at blood sugar level of:
A.
6 mmol/L
B.
5 mmol/L
C.
4 mmol/L
D.
3 mmol/L
E.
2 mmol/L
24.
The following symptom of hypoglycemia occurs at the following blood sugar level:
A.
Confusion - 4 mmol/L
B.
Coma – 1.7 mmol/L
C.
Convulsion – 3 mmol/L
D.
Permanent brain damage – 2 mmol/L
E.
All of the above
PHYSIOLOGY – ENDOCRINE SYSTEM - MCQ 4

25.
Basal secretion of Insulin occurs at:
A.
1 unit/hour
B.
2 unit/hour
C.
3 unit/hour
D.
4 unit/hour
E.
5 unit/hour
26.
Average amount of insulin secreted per day is:
A.
10 units/day
B.
20 units/day
C.
30 units/day
D.
40 units/day
E.
50 units/day
27.
Insulin release reduces with:
A.
Vagal stimulation
B.

adrenergic stimulation
C.
Hypokalaemia
D.
Glucagon
E.
None of the above
28.
Glucagon does NOT induce:
A.
hepatic glycogenolysis
B.
muscle glycogenolysis
C.
positive inotropic action in large doses
D.
increase hepatic gluconeogenesis
E.
lipolysis
29.
Glucagon is NOT stimulated by:
A.
protein diet
B.
starvation
C.
carbohydrate meal
D.

stimulation
E.
exercise, infection or other stressors.
30.
Which of the following is FALSE?
A.
Exogenous glucocorticoid administration induces secondary diabetes mellitus in all subjects.
B.
Thyroid hormone stimulates increased glucose absorption & hepatic glycogenolysis
C.
Exercise stimulat3es glucose entry into skeletal muscle & increase skeletal muscle insulin sensitivity
D.
Growth hormone is ketogenic & increases hepatic glucose output
E.
All of the above
PHYSIOLOGY – ENDOCRINE SYSTEM - MCQ 5

31.
Aldosterone is produced in:
A.
Zona glomerulosa
B.
Zona fasiculata
C.
Zona reticularis
D.
Zona fasiculata & Zona reticularis
E.
All of the above
32.
Catecholamines:
A.
adrenaline is formed from methylation of noradrenaline in plasma
B.
plasma levels of noradrenaline increased by 50-100% upon rising from supine to standing position
C.
All of the circulating dopamine is produced by adrenal medulla
D.
All catecholamines are excreted as VMA in urine
E.
All of the above is true.
33.
Which of the following regarding circulating catecholamines is FALSE?
A.
Circulating adrenaline stimulates vascular

receptor, resulting in a rise of diastolic & systolic blood pressure, & reflex bradycardia & reduced cardiac output.
B.
Circulating adrenaline & noradrenaline stimulates hepatic glycogenolysis
C.
Increased circulating adrenaline prolongs Hypokalaemia secondary to potassium sequestration into cells.
D.
Elevated circulating adrenaline & noradrenaline increases metabolic rate
E.
None of the above
34.
Levels of circulating adrenaline to cause the following:
A.
Tachycardia – 50pg/ml
B.

systolic BP – 75 pg/ml
C.

lipolysis – 75 pg/ml
D.

diastolic BP – 150 pg/ml
E.
All of the above
35.
Which of the following regarding dopamine is FALSE?
A.

systolic BP
B.

diastolic BP
C.

renal vasodilatation
D.
 git vasodilation
E.
positive inotropic action on the heart.
36.
Pick the correct order of increasing strength of glucocorticoid activity:
A.
Cortisol > corticosterone > cortisone > prednisolone > dexamethasone
B.
Corticosterone > cortisol > cortisone > prednisolone > dexamethasone
C.
Dexamethasone > prednisolone > cortisone > cortisol > corticosterone
D.
Prednisolone > cortisone > dexamethasone > cortisol > cortisone
E.
Dexamethasone > prednisolone > cortisol > corticosterone > cortisone
PHYSIOLOGY – ENDOCRINE SYSTEM - MCQ 6

37.
Which of the following has no mineralocorticoid activity?
A.
aldosterone
B.
cortisone
C.
prednisolone
D.
dexamethasone
E.
fludrocortisone
38.
Which of the following is TRUE?
A.
Zona glomerulosa does not produce cortisol or sex hormones because it lacks 17
 hydroxylase.
B.
Adrenocortical cells has abundant amount of LDL receptors
C.
ACTH binds to receptors at adrenocortical cells to stimulate increased cholesterol formation
D.
21

hydroxylase deficiency causes virulization
E.
All of the above
39.
Circulating free cortisol level reduces in:
A.
pregnancy
B.
multiple myeloma
C.
nephrosis
D.
cirrhosis
E.
none of the above
40.
Which of the following is TRUE regarding corticosteroid?
A.
Cortisone is synthesized in Zona fasciculata of adrenal gland
B.
Corticosterone binds more avidly to corticosteroid binding globulin (CGB) than cortisol.
C.
During stress, elevated circulating free cortisol levels is due to reduced hepatic metabolism
D.
Corticosteroids are excreted completely by urinary route
E.
All of the above
41.
Which of the following is TRUE regarding androgens?
A.
In male, 2/3 of urinary ketosteroid is from testicular origin.
B.
Adrenal androgens only have 20% activity of testosterone.
C.
Adrenal androgen production is controlled by pituitary gonadotrophin
D.
Plasma adrenal androgen concentration is same in both male & female
E.
All of the above
42.
Glucocorticoid :
A.
has end organ anti-insulin action (sparing heart & brain)
B.
has permissive action on catecholamine induced pressor & bronchodilator response.
C.
Acts to overall suppress T cell number & activity
D.
Stimulates increased number of neutrophils, platelets & red cells in circulation
E.
All of the above
PHYSIOLOGY – ENDOCRINE SYSTEM - MCQ 7

43.
In glucocorticoid excess (Cushing’s syndrome), the following metabolic changes occurs:
A.
Hypoglycemia
B.
Hypokalaemia
C.
Hyponatraemia
D.
Protein catabolism
E.
All of the above
44.
High dose steroid exerts anti-inflammatory action by:
A.
Stabilize lysosomal membrane
B.
Inhibits histamine release
C.
Inhibits fibroblastic action
D.
Inhibits IL-1 & inhibits arachidonic acid release from cell membrane, blocking systemic actions of bacterial toxins
E.
All of the above
45.
Which of the following stimulates glucocorticoid secretion?
A.
ACTH
B.
Angiotensin II
C.
Serotonin
D.
VIP
E.
All of the above
46.
Which of the following regarding primary hyperaldosteronism is FALSE?
A.
mild hypernatraemia
B.
hypokalaemia
C.
alkalosis
D.
oedema
E.
hypertension
47.
Which of the following regarding aldosterone is FALSE?
A.
Opens amiloride inhibitable sodium channels in basolateral membrane of renal tubular epithelial cells
B.
Increased number & activity of Na/K ATPase at the basolateral membrane of renal tubular epithelial cells.
C.
Sodium retention occurs at a lag time of 1-2 days
D.
Mineralocorticoid receptor binds cortisol with higher affinity than to aldosterone
E.
Mineralocorticoid sensitive tissue contains 11
 hydroxysteroid dehydrogenase to metabolize glucocorticoid.
48.
Which of the following does NOT occurs in Addison’s disease?
A.
Hyponatraemia
B.
Hyperkalaemia
C.
Metabolic acidosis
D.
Hypertension
E.
Hypoglycemia
PHYSIOLOGY – ENDOCRINE SYSTEM - MCQ 8

49.
Amount of ionized calcium in human plasma is:
A.
1.00mmol/L
B.
1.18mmol/L
C.
1.34mmol/L
D.
2.50mmol/L
E.
None of the above
50.
Which of the following regarding calcium is FALSE?
A.
Increased number of ionized calcium occurs with rising pH.
B.
60% of filtered calcium is reabsorped in proximal tubule.
C.
1,25 vitamin D acts to reduce intestinal calcium absorption in the intestine
D.
high protein diet increases calcium absorption in the intestine
E.
Hypocalcaemia in chronic renal failure is due to reduced formation of 1,25 vitamin D
51.
Inorganic phosphate is reabsorped in kidney at:
A.
proximal tubule
B.
loop of henle
C.
distal tubule
D.
collecting duct
E.
Inorganic phosphate is not reabsorped.
52.
Which hormone does NOT stimulate osteoblasts?
A.
Corticosteroid
B.
PTH
C.
Thyroid hormone
D.
1,25 vitamin D
E.
None of the above
53.
Where is 1,25 vitamin D mainly formed in the body?
A.
Skin
B.
Liver
C.
Proximal tubule of kidney
D.
Distal tubule of Kidney
E.
All of the above
54.
Action of 1,25 vitamin D include:
A.
Inhibits PTH
B.

intestinal calcium absorption via Ca/H ATPase
C.

Ca reabsorption in proximal & distal tubules
D.
Increased Ca mobilization from bone
E.
All of the above
PHYSIOLOGY – ENDOCRINE SYSTEM - MCQ 9

55.
Which of the following regarding PTH is FALSE?
A.
is metabolized by hepatic kuffer cells into inactive fragments
B.
circulating ionized Ca act directly on PTH gland to inhibit PTH release
C.
hypermagnesemia stimulates PTH release
D.
hyperphosphataemia stimulates PTH release
E.

adrenergic stimulation results in PTH release
56.
Action of PTH does NOT include:
A.
 Ca reabsorption from distal tubule
B.

PO4 excretion
C.

bone resorption
D.
direct

Ca absorption from intestine
E.
stimulates osteoclasts & osteoblasts
57.
PTHrP is secreted in the following tumors:
A.
breast carcinoma
B.
renal cell carcinoma
C.
ovarian carcinoma
D.
skin cancer
E.
all of the above
58.
Which of the following pairing of hormone & their action is FALSE?
A.
Calcitonin – increased Ca excretion
B.
Glucocorticoid – reduced Ca absorption from intestine
C.
Growth hormone – increased Ca absorption from intestine
D.
PTHrP – reduced Ca filtration at the glomeruli
E.
All of the above
59.
Metabolic action of Growth hormone does NOT include:
A.

free circulating amino acids
B.

circulating free fatty acids
C.

hepatic glucose output
D.
anti-insulin effect on muscle
E.

pancreas sensitivity to glucose
60.
Action of growth hormone does NOT include:
A.
Epiphyseal growth
B.
Sodium retention
C.
Epiphyseal closure
D.
All of the above
E.
None of the above
PHYSIOLOGY – ENDOCRINE SYSTEM - MCQ 10

ANSWERS:
1.
C
2.
B
3.
A
4.
C
5.
D
6.
C
7.
E
8.
C
9.
A
10.
B
11.
D
12.
A
13.
E
14.
A
15.
C
16.
B
17.
D
18.
A
19.
D
20.
E
21. B
22. D
23. C
24. B
25. A
26. D
27. C
28. B
29. C
30. A
31. A
32. B
33. A
34. E
35. B
36. C
37. D
38. E
39. E
40. C
41. D
42. E
43. B
44. E
45. A
46. D
47. C
48. D
49. B
50. C
51. A
52. A
53. C
54. E
55. C
56. D
57. E
58. D
59. A
60. C
POSSIBLE VIVA TOPICS:
1.
Describe the synthesis & action of thyroid hormone.
2.
Insulin
3.
Describe the development of DKA.
4.
Type I vs Type 2 diabetes mellitus
5.
Action profile of glucocorticoids
6.
Physiological basis of Cushing’s syndrome.
Note from Louis: 15 should be D – it is internalized w/ receptor and broken down
PHYSIOLOGY – ENDOCRINE SYSTEM - MCQ 11