Which of the following structures in the adrenal glands secretes epinephrine?

Correct Answer: C

Rationale: Chromaffin cells in the adrenal medulla secrete epinephrine, not cortical zones (glomerulosa: aldosterone, fasciculata: cortisol, reticularis: androgens). This distinguishes catecholamine production, key to acute stress, contrasting with steroid zones.

Correct Answer: B

Rationale: Negative feedback controls most endocrine secretions (e.g., high cortisol suppresses ACTH), maintaining homeostasis excess inhibits production. Positive feedback (e.g., oxytocin in labor) is rare, amplifying. Neural feedback is specific (e.g., medulla), not broad. Hormonal is a type, not the system. Negative feedback distinguishes endocrine stability, key to regulation, unlike amplifying or partial mechanisms.

Correct Answer: B

Rationale: Hypothalamus produces ADH (water) and oxytocin (labor), stored/released by posterior pituitary neurohypophyseal pair. Aldosterone is adrenal, not hypothalamic. Prolactin is anterior pituitary, not posterior. Cortisol is adrenal cortex, unrelated. ADH-oxytocin duo distinguishes posterior pituitary function, key to hypothalamic delivery, unlike adrenal or anterior hormones.

Correct Answer: C

Rationale: GH overproduction in adults causes acromegaly bone thickening (e.g., hands, face) post-epiphyseal closure. Dwarfism is childhood GH lack. Gigantism is pre-closure excess height surge. Myxedema is hypothyroidism, unrelated. Acromegaly's adult-specific bone changes distinguish it, key to GH excess timing, unlike childhood or thyroid conditions.

Correct Answer: D

Rationale: PTH (parathyroid) raises blood calcium by bone resorption, opposing calcitonin's lowering via deposition antagonistic pair. Thyroxine (thyroid) boosts metabolism, not calcium directly. GH (pituitary) grows bones, not regulating calcium. Insulin (pancreas) lowers glucose, unrelated. PTH's calcium-raising role distinguishes it, key to homeostasis, unlike metabolic, growth, or glucose hormones.