The hypothalamic-hypophyseal tract ________.

Correct Answer: B

Rationale: The correct answer is B because the hypothalamic-hypophyseal tract is indeed partly contained within the infundibulum, which is a stalk-like structure connecting the hypothalamus to the pituitary gland. This pathway is crucial for the release of hormones from the hypothalamus to the pituitary gland. Choice A is incorrect as the hypophysis and pituitary gland are the same structure. Choice C is incorrect as aldosterone is a hormone produced by the adrenal glands, not related to the hypothalamic-pituitary axis. Choice D is incorrect because prolactin synthesis occurs in the lactotroph cells of the anterior pituitary, not in the hypothalamic-hypophyseal tract.

Correct Answer: C

Rationale: The correct answer is C: An amino acid derivative can be a hormone. This statement is correct because many hormones are derived from amino acids, such as thyroid hormones (derived from tyrosine) and epinephrine (derived from phenylalanine). Hormones can be derived from various sources, including amino acids, peptides, lipids, and even gases. Explanation of other choices: A: Prostaglandins are not biologically active peptides; they are lipid compounds derived from fatty acids. B: Modified cholesterol does not form the main structural component of peptone hormones; peptides are the main structural components of peptide hormones. D: Testosterone is a steroid hormone and not an example of a paracrine, which is a type of chemical messenger that acts on nearby cells.

Correct Answer: D

Rationale: The correct answer is D: excessively high blood iodine concentrations. High blood iodine levels do not inhibit TSH release; they actually stimulate it. Growth hormone-inhibiting hormone (GHIH), rising levels of glucocorticoids, and somatostatin are all factors that inhibit TSH release. GHIH inhibits TSH release by acting on the pituitary gland. Glucocorticoids have a negative feedback effect on the hypothalamus and pituitary gland, reducing TSH release. Somatostatin inhibits the release of various hormones, including TSH.

Correct Answer: C

Rationale: The correct answer is C: Pituitary gland. The pituitary gland is an endocrine gland located at the base of the brain, below the hypothalamus. It secretes various hormones that regulate important functions in the body. The other choices are incorrect because: A: Adrenal gland - located on top of the kidneys, not in the brain. B: Pancreas - located in the abdomen, not in the brain. D: Parathyroid glands - located in the neck, not in the brain.

Correct Answer: D

Rationale: The correct answer is D: adrenal cortex. ACTH stimulates the adrenal cortex to produce and release its hormones, including cortisol. The anterior pituitary produces ACTH, but it does not release hormones itself. The adrenal medulla is primarily stimulated by the sympathetic nervous system, not ACTH. The kidneys are not directly stimulated by ACTH to produce and release hormones. Therefore, the adrenal cortex is the correct choice as it directly responds to ACTH stimulation.