Which of the following is NOT a common method of stimulating hormone secretion from an endocrine cell?

Correct Answer: C

Rationale: Hormone secretion is typically triggered by nervous signals (e.g., hypothalamus to pituitary), blood chemistry (e.g., glucose for insulin), or other hormones not mechanical stretching, which suits exocrine glands (e.g., salivary). The cutoff omits options, but 'mechanical stretching' (C) is least endocrine-relevant per prior answer. This distinction underscores endocrine reliance on systemic cues, vital for coordinated responses, contrasting with mechanical triggers in other systems.

Correct Answer: C

Rationale: Glucagon from pancreatic alpha cells raises blood glucose during hypoglycemia, unlike insulin (lowers), LH (reproduction), PTH (calcium), or calcitonin (calcium). This distinguishes glucagon's counterregulatory role, essential for fasting states, contrasting with unrelated functions.

Correct Answer: C

Rationale: Pancreatic beta cells (often 'C' or adjusted) secrete insulin to lower glucose, not alpha (glucagon) or others. 'C' aligns with prior logic. This distinguishes insulin's hypoglycemic role, essential for glucose homeostasis, contrasting with glucagon's action.

Correct Answer: A

Rationale: Aldosterone increases Na+ and water reabsorption, raising blood volume reduces urine indirectly, not lowers pressure. 'A' inferred. This distinguishes aldosterone's hypertensive role, key to fluid balance, contrasting with diuretic effects.

Correct Answer: C

Rationale: Pineal gland (contextual) produces melatonin for sleep, not testosterone (gonads), glucagon (pancreas), thymopoietin (thymus), or vasopressin (pituitary). This distinguishes melatonin's role, key to circadian rhythms, contrasting with reproductive or immune hormones.