Which gland secretes TSH, ACTH, and growth hormone?

Correct Answer: D

Rationale: The correct answer is D, the anterior pituitary gland, because it secretes TSH, ACTH, and growth hormone. The anterior pituitary gland is also known as the adenohypophysis, and it plays a key role in regulating various bodily functions through the release of different hormones. The other choices are incorrect because the neurohypophysis (choice A) secretes hormones like oxytocin and vasopressin, the pancreas (choice B) secretes insulin and glucagon, and the adrenal medulla (choice C) secretes adrenaline and noradrenaline.

Correct Answer: D

Rationale: Step 1: Cretinism, myxedema, and Graves' disease are all related to thyroid gland function. Step 2: Cretinism is a congenital hypothyroidism, myxedema is adult hypothyroidism, and Graves' disease is hyperthyroidism. Step 3: Thus, they are all disorders of thyroid gland function. Summary: - Choice A is incorrect because they are not all thyroid hormone deficiency diseases. - Choice B is incorrect because they are not all caused by oversecretion of thyroxine. - Choice C is incorrect because they are not primarily related to calcium imbalances due to lack of calcitonin.

Correct Answer: B

Rationale: The correct answer is B: A benign tumor of the adrenal medulla is called a pheochromocytoma. Pheochromocytomas are tumors that arise from the adrenal medulla, leading to overproduction of catecholamines like adrenaline and noradrenaline. This excess secretion can result in symptoms such as high blood pressure, palpitations, and sweating. Choices A and C are incorrect because a benign tumor of the adrenal medulla typically causes high blood pressure, not low blood pressure or Addison's disease. Choice D is incorrect because excess cortisol secretion is associated with conditions like Cushing's syndrome, not pheochromocytoma.

Correct Answer: B

Rationale: The correct answer is B because as plasma levels of calcium decrease, the parathyroid glands secrete an osteoclastic hormone called parathyroid hormone (PTH). PTH acts to increase calcium levels by stimulating the release of calcium from bones via osteoclasts. Insulin secretion (choice A) is not directly related to calcium levels. The kidneys excreting calcium and phosphorus (choice C) would further decrease calcium levels. Calcitonin (choice D) actually decreases blood calcium levels by inhibiting bone breakdown, so it is not secreted when calcium levels decrease.

Correct Answer: B

Rationale: The correct answer is B. The pituitary gland does not directly control the parathyroid gland secretion of PTH. The pituitary gland is responsible for secreting hormones that regulate other endocrine glands, such as adrenal cortex (A), thyroid gland (C), and ovaries (D). In contrast, the parathyroid gland is primarily regulated by the calcium levels in the blood, not directly by the pituitary gland. Therefore, choices A, C, and D are incorrect as they are all glands whose secretions are directly controlled by the pituitary gland.