Which of the following is NOT a type of hormone stimulus?

Correct Answer: D

Rationale: The correct answer is D, receptor-mediated stimulus. Hormones can be stimulated by hormonal, humoral, or neural factors, but not directly by receptors. Hormonal stimulus involves other hormones triggering hormone release, humoral stimulus involves changing blood levels of ions or nutrients triggering hormone release, and neural stimulus involves direct nerve stimulation triggering hormone release. Receptor-mediated stimulus is not a recognized type of hormone stimulus because hormones do not directly respond to receptors in this context.

Correct Answer: B

Rationale: The correct answer is B because free fatty acid mobilization is primarily regulated by cortisol, not dehydroepiandrosterone. Cortisol promotes lipolysis and stimulates the release of free fatty acids from adipose tissue. Dehydroepiandrosterone is a precursor hormone mainly involved in sex hormone production and has minimal effects on free fatty acid mobilization. Choices A, C, and D are correctly paired as gluconeogenesis is stimulated by cortisol, muscle glycogenolysis is regulated by epinephrine, and kaliuresis is induced by aldosterone.

Correct Answer: B

Rationale: The correct answer is B: controls the amount of urine one produces. Antidiuretic hormone (ADH) acts on the kidneys to regulate water reabsorption, thereby controlling the amount of urine produced. It does not control metabolic rate (A), increase blood sugar (C), or control reproduction (D). ADH's main function is to maintain water balance in the body by reducing urine output.

Correct Answer: B

Rationale: The correct answer is B: Thyroid. The body's major metabolic hormone, thyroxine (T4) and triiodothyronine (T3), is released from the thyroid gland. The thyroid gland plays a crucial role in regulating metabolism. Pituitary (A) releases various hormones but not the major metabolic hormone. Thymus (C) is responsible for immune function, not metabolism. Hypothalamus (D) regulates the pituitary gland but does not directly release the major metabolic hormone.

Correct Answer: C

Rationale: The correct answer is C: anterior pituitary. Hypothalamic releasing hormones target cells in the anterior pituitary to stimulate the release of specific pituitary hormones. The hypothalamus produces releasing hormones that travel through the hypophyseal portal system and bind to receptors on cells in the anterior pituitary, triggering the release of hormones such as ACTH, TSH, LH, FSH, and GH. This interaction between the hypothalamus and anterior pituitary forms the hypothalamic-pituitary axis, regulating various physiological processes. Choices A (thyroid) and D (posterior pituitary) are incorrect as they are not the primary targets of hypothalamic releasing hormones. Choice B (hypothalamus) is also incorrect as releasing hormones do not target cells within the hypothalamus itself, but rather the anterior pituitary.