Endocrinology Practice Questions

Correct Answer: C

Rationale: The correct answer is C: Stress. Stress triggers the release of growth hormone through the activation of the hypothalamic-pituitary-adrenal axis. When the body is under stress, the hypothalamus signals the pituitary gland to release growth hormone. This hormone then stimulates growth and cell reproduction. Glucocorticoids (A) and somatostatin (B) actually inhibit the release of growth hormone. Obesity (D) can lead to decreased growth hormone release due to disrupted hormonal regulation. In summary, stress is the correct answer as it directly stimulates the release of growth hormone, while the other choices inhibit or have a negative impact on growth hormone release.

Correct Answer: A

Rationale: The correct answer is A: Phaeochromocytoma. Multiple Endocrine Neoplasia Type I (MEN I) is characterized by tumors in the pituitary, pancreas, and parathyroid glands. Phaeochromocytoma is not typically associated with MEN I. Phaeochromocytoma is commonly seen in MEN II syndrome. Therefore, A is the correct answer. Choice B, C, and D are incorrect as they are all associated with MEN I based on the characteristic tumor involvement in the pituitary, pancreas, and parathyroid glands, respectively.

Correct Answer: C

Rationale: Elevated glucose levels in obese individuals are often due to insulin resistance. Insulin resistance occurs when the body's cells do not respond effectively to insulin, leading to decreased glucose uptake. This results in elevated blood glucose levels. Diabetic acidosis (choice A) is a complication of uncontrolled diabetes characterized by high blood ketone levels, not directly related to obesity. Glucose intolerance (choice B) refers to the body's inability to regulate blood glucose levels efficiently but is not specific to obesity. Insulin deficiency (choice D) is characteristic of type 1 diabetes, where the body does not produce enough insulin, which is distinct from insulin resistance seen in obesity.

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: Erythropoietin is primarily secreted from the kidney, specifically by the Juxtaglomerular cells in the kidney's cortex. These cells are responsible for sensing oxygen levels and regulating erythropoietin production accordingly. Mesenchymal tumors, cerebellar haemangioblastoma, and lymphoma are not associated with erythropoietin secretion, making them incorrect choices. Mesenchymal tumors originate from connective tissues, cerebellar haemangioblastoma is a type of brain tumor, and lymphoma is a cancer of the lymphatic system. Only the Juxtaglomerular cells in the kidney have the physiological role of secreting erythropoietin in response to hypoxia.