ADH ________.

Correct Answer: D

Rationale: The correct answer is D because alcohol inhibits the release of antidiuretic hormone (ADH) from the pituitary gland. ADH helps regulate water balance by promoting water reabsorption in the kidneys, reducing urine output. Alcohol impairs this process, leading to increased urine production and dehydration. Choices A, B, and C are incorrect because ADH decreases urine production, prevents dehydration, and is produced in the neurohypophysis (posterior pituitary), not the adenohypophysis (anterior pituitary).

Correct Answer: B

Rationale: Correct Answer: B - Secretion of ACTH is regulated by a hypothalamic secretion. Rationale: 1. The hypothalamus secretes corticotropin-releasing hormone (CRH). 2. CRH stimulates the anterior pituitary to release adrenocorticotropic hormone (ACTH). 3. ACTH then stimulates the adrenal cortex to release cortisol. 4. This feedback loop demonstrates how ACTH secretion is regulated by a hypothalamic secretion. Summary: A - Incorrect. ACTH is secreted by the anterior pituitary, not the posterior pituitary. C - Incorrect. ACTH causes the release of hormones from the adrenal cortex, not the adrenal medulla. D - Incorrect. ACTH is a tropic hormone as it acts on another endocrine gland (adrenal cortex).

Correct Answer: B

Rationale: The correct answer is B: hormones. Hormones are chemical signals produced by glands that travel through the bloodstream to affect the behavior of other glands and tissues. Enzymes (choice A) are catalysts for chemical reactions, not signaling molecules. Carbohydrates (choice C) are energy sources and structural components, not signaling molecules. Metabolites (choice D) are the byproducts of metabolism, not signaling molecules. Hormones are specifically designed to regulate physiological processes in the body by acting on target cells, making them the most fitting choice among the options provided.

Correct Answer: B

Rationale: The correct answer is B: anterior pituitary gland. The hypothalamus secretes releasing and inhibiting hormones that travel to the anterior pituitary gland through the hypophyseal portal system, where they regulate the production and secretion of various hormones. This control mechanism ensures proper hormonal balance in the body. Choices A, C, and D are incorrect because the adrenal cortex, posterior pituitary gland, and thyroid gland are not directly regulated by the hypothalamus through releasing and inhibiting hormones.

Correct Answer: D

Rationale: The correct answer is D: Thyroid gland. The thyroid gland requires iodine to produce its hormones, such as thyroxine and triiodothyronine, which are essential for regulating metabolism, growth, and development. Iodine is a crucial component of these thyroid hormones. The other choices (A: Adrenal cortex, B: Pancreas, C: Parathyroid glands) do not require iodine for hormone production and are not involved in the synthesis of thyroid hormones. Therefore, the correct answer is the thyroid gland because it specifically relies on iodine for hormone synthesis, making it the only gland in the list that fits this criteria.