Which of the following is true of the hypothalamus?

Correct Answer: A

Rationale: The correct answer is A because the hypothalamus secretes releasing hormones into the portal capillaries, which then travel to the anterior pituitary to regulate hormone secretion. This is known as the hypothalamic-pituitary axis. Choices B and C are incorrect because the hypothalamus is not composed of glandular tissue and it is not called the adenohypophysis. Choice D is incorrect because the connection between the hypothalamus and the neurohypophysis is via the hypothalamic-hypophyseal tract, not through the portal capillaries.

Correct Answer: A

Rationale: The correct answer is A because the posterior pituitary gland is an extension of the hypothalamus. The hypothalamus produces hormones that are stored and released by the posterior pituitary gland. This connection between the two structures allows for direct neural control over hormone release. Option B is incorrect because the neurohypophysis does not secrete releasing hormones; rather, it releases hormones produced by the hypothalamus. Option C is incorrect because the posterior pituitary gland does not regulate adenohypophyseal function; instead, it stores and releases hormones produced by the hypothalamus. Option D is incorrect because the posterior pituitary gland does not secrete releasing hormones; it releases hormones produced by the hypothalamus.

Correct Answer: B

Rationale: The correct answer is B because a hormone that suppresses gluconeogenesis helps to prevent hyperglycemia by inhibiting the production of glucose in the liver. This hormone regulates blood sugar levels by reducing the formation of new glucose molecules. Choice A is incorrect because increasing renal excretion of sodium and water is related to the regulation of fluid balance, not gluconeogenesis. Choice C is incorrect because causing diuresis involves increasing urine production and is not directly related to suppressing gluconeogenesis. Choice D is incorrect because causing hypocalcemia refers to low levels of calcium in the blood and is not associated with the suppression of gluconeogenesis.

Correct Answer: C

Rationale: The correct answer is C: beta cells. Beta cells in the pancreas secrete insulin, which helps decrease blood glucose levels by facilitating the uptake of glucose into cells for energy production. Delta cells (choice A) secrete somatostatin, which inhibits insulin and glucagon secretion. Alpha cells (choice B) secrete glucagon, which increases blood glucose levels. Choice D is a duplicate of choice C. Therefore, the correct answer is C as beta cells play a crucial role in regulating blood glucose levels through insulin secretion.

Correct Answer: C

Rationale: The correct answer is C, Gnadocorticoids, such as the androgens. The adrenal glands produce androgens like DHEA which can supplement sex hormones from the gonads. Choice A, mineralocorticoids, control electrolyte and water balance. Choice B, glucocorticoids, regulate metabolism and immune response. Choice D, epinephrine and norepinephrine, are involved in the fight or flight response. Gnadcorticoids, specifically androgens, are the hormones from the adrenal glands that can supplement sex hormones from the gonads, making choice C the correct answer.