Vanillylmandelic acid (VMA) excretion is increased in urine in:
- A. Conn's syndrome
- B. Congenital adrenal hyperplasia
- C. Testicular feminization syndrome
- D. Phaeochromocytoma
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.
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Tetany is characterized by all of the following signs except:
- A. Trousseau's sign
- B. Tinel's sign
- C. Erb's sign
- D. Peroneal sign
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.
Myxoedema coma is characterized by:
- A. Hypertension
- B. Tachycardia
- C. Euthermia
- D. Hypoventilation
Correct Answer: B
Rationale: Myxoedema coma is a severe form of hypothyroidism that can lead to the slowing down of various body functions, including reduced heart rate (bradycardia). As the condition progresses and the body's metabolism becomes more depressed, one of the compensatory mechanisms is an increase in heart rate (tachycardia) to try to maintain adequate tissue perfusion. Therefore, tachycardia is a characteristic feature of myxoedema coma, rather than hypertension or euthermia which are not typically associated with this condition. Hypoventilation is also a common feature of myxoedema coma due to the decreased metabolic rate and respiratory drive.
Commonest cause of Addison's disease is:
- A. Granuloma
- B. Idiopathic atrophy
- C. Inflammatory necrosis
- D. Malignancy
Correct Answer: A
Rationale: The most common cause of Addison's disease is autoimmune adrenalitis, also known as autoimmune adrenal insufficiency. In autoimmune adrenalitis, the adrenal glands are damaged by immune system-mediated processes, leading to their dysfunction. This autoimmune destruction typically presents as bilateral adrenal cortex atrophy due to the formation of granulomas. Therefore, the commonest cause of Addison's disease is the presence of granulomas in the adrenal glands, making option A, Granuloma, the correct choice.
Effect of diabetes on foetus includes all except:
- A. Microsomia
- B. Hyperbilirubinaemia
- C. Stillbirth
- D. Open neural tube defect
Correct Answer: B
Rationale: Hyperbilirubinemia is not a common effect of diabetes on the fetus. The correct effects of diabetes on the fetus include:
All the following are effects of hypercalcemia except
- A. Diarrhea
- B. Polyuria
- C. A shortened qt interval
- D. Nephrolithiasis
Correct Answer: C
Rationale: Hypercalcemia refers to elevated levels of calcium in the blood. The effects of hypercalcemia include increased urinary frequency (polyuria), gastrointestinal symptoms such as constipation rather than diarrhea, kidney stones (nephrolithiasis), and various cardiac abnormalities. One key cardiac abnormality associated with hypercalcemia is a prolonged QT interval rather than a shortened QT interval. Prolongation of the QT interval can predispose individuals to arrhythmias, particularly Torsades de pointes. Therefore, the correct answer is C, as a shortened QT interval is not a typical effect of hypercalcemia.