Endocrinology Practice Questions

Correct Answer: C

Rationale: The correct answer is C: Neovascularization. Non-proliferative diabetic retinopathy is characterized by early changes such as retinal vascular microaneurysms, blot hemorrhages, and cotton-wool spots. Neovascularization is a feature of proliferative diabetic retinopathy, not non-proliferative. Neovascularization refers to the growth of abnormal new blood vessels in the retina, which can lead to severe vision loss if not treated promptly. In summary, neovascularization is not consistent with non-proliferative diabetic retinopathy, as it is a hallmark of the proliferative stage.

Correct Answer: C

Rationale: The correct answer is C: Myxoedema. Myxoedema is associated with hypothyroidism, not SIADH. Guillain-Barre syndrome, subacute bacterial endocarditis, and bronchogenic carcinoma are all conditions that can lead to SIADH due to various mechanisms. Guillain-Barre syndrome can cause SIADH through autonomic dysfunction, endocarditis through the release of inflammatory cytokines, and bronchogenic carcinoma through production of ectopic ADH. Therefore, myxoedema is the only incorrect choice as it does not typically lead to SIADH.

Correct Answer: D

Rationale: The correct answer is D: Fine hairs. In secondary hypothyroidism, the pituitary gland fails to produce enough thyroid-stimulating hormone (TSH), resulting in low thyroid hormone levels. Fine hairs (or hair thinning) is a symptom of hyperthyroidism, not hypothyroidism. Normal cholesterol levels (Choice A) are seen in secondary hypothyroidism due to decreased metabolic rate. Menorrhagia (Choice B) can occur due to hormonal imbalances caused by untreated hypothyroidism. Low TSH levels (Choice C) are a characteristic feature of secondary hypothyroidism as the pituitary gland is not producing enough TSH to stimulate the thyroid gland.

Correct Answer: A

Rationale: The correct answer is A because ADH secretion is increased during stress to retain water in the body. This response helps maintain blood pressure and prevent dehydration under stressful conditions. Choice B is incorrect because ADH secretion is actually increased during hemorrhage to conserve water. Choice C is incorrect because increased blood osmolality triggers ADH secretion to retain water. Choice D is incorrect because alcohol inhibits ADH secretion, leading to increased urine production.

Correct Answer: C

Rationale: Step-by-step rationale: 1. Tertiary hyperparathyroidism occurs due to prolonged secondary hyperparathyroidism in response to chronic renal failure. 2. In chronic renal failure, impaired kidney function leads to reduced activation of vitamin D and impaired calcium regulation. 3. Persistent hypocalcemia triggers the parathyroid glands to overproduce parathyroid hormone, leading to tertiary hyperparathyroidism. 4. Rickets (choice A) is associated with vitamin D deficiency, pseudohypoparathyroidism (choice B) is a genetic disorder, and malabsorption syndrome (choice D) affects nutrient absorption, but they are not commonly linked to tertiary hyperparathyroidism.