Endocrinology Practice Questions

Correct Answer: D

Rationale: The correct answer is D because the anterior pituitary is regulated by hypothalamic neuropeptides. The hypothalamus secretes releasing and inhibiting hormones that control the anterior pituitary's hormone release. This close interaction between the hypothalamus and the anterior pituitary is known as the hypothalamic-pituitary axis. A is incorrect because the anterior pituitary is not neural tissue, it is an endocrine gland. B is incorrect because the anterior pituitary synthesizes and secretes peptide hormones, not steroid hormones. C is incorrect because the anterior pituitary is located at the base of the brain, not above the kidney.

Correct Answer: C

Rationale: The correct answer is C because dipsogenic diabetes insipidus is caused by a defect or damage to the hypothalamus, not the pituitary gland or pituitary stalk. The hypothalamus regulates thirst and water intake, so damage to this area can lead to excessive thirst and dilute urine output characteristic of diabetes insipidus. Choices A and D incorrectly attribute the cause to the pituitary gland or pituitary stalk, which are not directly involved in regulating thirst. Choice B is incorrect as it mentions malfunction of the hunger mechanism, which is not relevant to dipsogenic diabetes insipidus. Thus, choice C is the most accurate definition based on the pathophysiology of the condition.

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: A

Rationale: The correct answer is A: Adrenaline. In injury to the adrenal cortex, adrenaline is least affected because it is primarily synthesized and secreted by the adrenal medulla, not the adrenal cortex. Cortisol, aldosterone, and androstenedione are hormones produced by the adrenal cortex. In adrenal cortex injury, the secretion of cortisol, aldosterone, and androstenedione would be significantly affected due to the damage to the adrenal cortex, leading to hormonal imbalance and related symptoms. Therefore, option A is the correct answer as it is not primarily secreted by the adrenal cortex and would be least affected in this scenario.

Correct Answer: B

Rationale: The correct answer is B: Weight loss. Hypothyroidism is characterized by an underactive thyroid gland, leading to a decreased metabolic rate. This typically results in weight gain, not weight loss. Choices A, C, and D are all associated with hypothyroidism. Loss of libido can occur due to hormonal imbalances, cardiac failure can result from the decreased metabolic rate affecting the heart, and organic psychosis can be a symptom of severe untreated hypothyroidism.