The superior suprarenal artery arises from:

Correct Answer: B

Rationale: The correct answer is B: Inferior phrenic artery. The superior suprarenal artery arises from the inferior phrenic artery, which supplies blood to the adrenal gland. The inferior phrenic artery originates from the abdominal aorta, near the celiac trunk. It is important to note that the adrenal glands receive blood supply from multiple sources, including the inferior phrenic artery. The other choices (A: Abdominal aorta, C: Renal artery, D: Superior mesenteric artery) do not directly supply blood to the adrenal glands, making them incorrect options.

Correct Answer: b

Rationale: The correct answer is B because smooth muscle does not utilize troponin to help initiate muscle contraction. Instead, smooth muscle contraction is regulated by calcium-calmodulin complex. A: True - Smooth muscle usually forms 2 layers at right angles to each other. C: True - Smooth muscle contains no striations. D: False - Action potentials in smooth muscle travel slowly via gap junctions, not tight junctions.

Correct Answer: B

Rationale: The correct answer is B because the adenohypophysis refers specifically to the anterior pituitary gland, which secretes various hormones like growth hormone, prolactin, and thyroid-stimulating hormone. Choice A is incorrect because ADH and oxytocin are actually secreted by the neurohypophysis (posterior pituitary). Choice C is incorrect because releasing hormones are secreted by the hypothalamus, not the adenohypophysis. Choice D is incorrect because glucocorticoids, mineralocorticoids, and androgens are actually secreted by the adrenal cortex, not the anterior pituitary gland.

Correct Answer: A

Rationale: Testosterone is best described as virilizing because it is the primary male sex hormone responsible for the development of male characteristics such as facial hair, deep voice, and muscle mass. It plays a key role in virilization. The other choices, lactogenic, adenohypophyseal, and pancreatic, are incorrect because testosterone is not primarily associated with lactation, the anterior pituitary gland, or the pancreas.

Correct Answer: D

Rationale: The correct answer is D: It increases plasma levels of calcium. Parathyroid hormone (PTH) acts to increase calcium levels in the blood by stimulating the release of calcium from bones, enhancing calcium absorption in the intestines, and reducing calcium excretion in the kidneys. This process helps maintain proper calcium levels in the blood. Choices A, B, and C are incorrect because PTH does not cause the excretion of calcium in the urine (A), stimulate osteoblastic activity to form bone (B), or stimulate the thyroid gland to secrete calcitonin (C).