Cretinism, myxedema, and Graves’ disease are all:

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 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.

Correct Answer: C

Rationale: Rationale: Myxedema, Graves' disease, and cretinism are all disorders directly related to the thyroid gland, involving either hypo or hyperactivity. Myxedema and cretinism are hypothyroid disorders, while Graves' disease is a hyperthyroid disorder. Thus, the correct answer is C. Choice A is incorrect as Graves' disease is a hyperthyroid disorder. Choice B is incorrect as these disorders are not solely due to a deficiency of TSH. Choice D is incorrect as treatment can vary depending on the specific disorder and may not always involve T3 and/or T4.

Correct Answer: C

Rationale: The correct answer is C (Pancreas, parathyroid, anterior pituitary) because glucagon is secreted by the pancreas, PTH (parathyroid hormone) is secreted by the parathyroid glands, and TSH (thyroid-stimulating hormone) is secreted by the anterior pituitary gland. Choice A (Neurohypophysis, pancreas, ovary) is incorrect because the neurohypophysis secretes oxytocin and ADH, not glucagon, PTH, or TSH. The ovary does not secrete any of these hormones. Choice B (Adrenal cortex, pancreas, neurohypophysis) is incorrect because the adrenal cortex secretes cortisol and aldosterone, not glucagon, PTH, or TSH. The neurohypophysis secretes oxytocin and ADH, not the hormones in question. Choice D (Testes, thymus, adenohypophysis