Endocrinology Exam Questions

Correct Answer: A

Rationale: Centripetal obesity, acne, and hirsutism are classic features of Cushing's syndrome. Cushing's syndrome results from prolonged exposure to high levels of cortisol, which can be due to various causes such as adrenal tumors, pituitary adenomas, or exogenous glucocorticoid use. Centripetal obesity refers to the characteristic fat distribution pattern seen in Cushing's syndrome, where fat accumulates mainly in the face, neck, and trunk while sparing the limbs. Acne and hirsutism are also commonly seen in Cushing's syndrome due to the hormonal imbalances caused by excess cortisol. Testing for serum cortisol levels, dexamethasone suppression tests, and imaging studies can help confirm the diagnosis of Cushing's syndrome in a patient presenting with these symptoms.

Correct Answer: A

Rationale: Thyroid hormones, T3 (triiodothyronine) and T4 (thyroxine), play a crucial role in regulating metabolism in the body. They are responsible for increasing the metabolic rate of cells by influencing the production of proteins and controlling how the body uses energy. This increase in metabolic rate results in processes such as increased heart rate, enhanced nutrient breakdown, and higher body temperature. Thus, option A, "increase metabolic rate," is the correct statement regarding thyroid hormones (T3 and T4).

Correct Answer: D

Rationale: Vanillylmandelic acid (VMA) is a metabolite of catecholamines, such as epinephrine and norepinephrine. Phaeochromocytoma is a catecholamine-secreting tumor that arises from the chromaffin cells in the adrenal medulla or sympathetic ganglia. As a result of the increased production of catecholamines in patients with phaeochromocytoma, there is an increase in VMA excretion in the urine. This increase in VMA excretion is a significant diagnostic feature of phaeochromocytoma and helps in its detection through urine testing. Therefore, the correct choice is D. Phaeochromocytoma.

Correct Answer: D

Rationale: Ranitidine is not associated with an increased risk of osteoporosis in adults. It is a histamine-2 blocker commonly used to reduce stomach acid production and treat conditions such as ulcers and gastroesophageal reflux disease. On the other hand, the other options listed are known to increase the risk of osteoporosis:

Correct Answer: C

Rationale: Tetany is a condition characterized by involuntary muscle spasms and contractions due to low levels of calcium in the blood. The signs associated with tetany include Trousseau's sign, which is the carpal spasm elicited by inflating a blood pressure cuff above systolic pressure, and Chvostek's sign, which is the facial muscle spasm elicited by tapping on the facial nerve. Peroneal sign is not specifically associated with tetany but can be seen in conditions like peroneal nerve injury. Erb's sign, on the other hand, is not a recognized sign of tetany. It is associated with Erb's palsy, a condition resulting from injury to the brachial plexus nerves, typically during childbirth. Tinel's sign, which is a tingling sensation elicited by tapping over a compressed nerve, is also not a characteristic sign of tetany.