Endocrine glands

Correct Answer: C

Rationale: Endocrine glands produce hormones chemical messengers like insulin or cortisol that enter the bloodstream, targeting distant organs to regulate processes like metabolism. Unlike exocrine glands (e.g., sweat, sebaceous) using ducts, or neurons releasing neurotransmitters into synapses, endocrine glands' blood-mediated delivery defines them. Sebaceous and sweat glands are exocrine, not endocrine. This circulatory transport distinguishes endocrine function, critical for systemic coordination, contrasting with localized synaptic or ductal mechanisms.

Correct Answer: D

Rationale: Fight-or-flight, driven by adrenal medulla catecholamines, includes pupil dilation (vision), increased lung oxygen (energy), and suppressed digestion (blood diversion). Mental activity heightens for alertness, not reduces. Reduced cognition contradicts this survival mechanism, distinguishing it from physiological shifts, key to acute stress response understanding.

Correct Answer: D

Rationale: The renin-angiotensin-aldosterone system (RAAS) raises blood pressure: renin (kidneys) triggers angiotensin II, constricting vessels, and aldosterone, retaining sodium/water. It doesn't lower volume/pressure or raise glucose. Pressure elevation distinguishes RAAS's role, critical for hypotension response, contrasting with glucose or volume reduction effects.

Correct Answer: A

Rationale: The posterior pituitary produces zero hormones it stores and releases ADH and oxytocin, synthesized by hypothalamic neurons, via the hypothalamic-hypophyseal tract. 'One' or 'two' suggest production (e.g., ADH, oxytocin), but neurohypophysis lacks glandular synthesis, unlike anterior pituitary (e.g., TSH). 'Three' exceeds known outputs no third hormone exists. Its role as a neural extension for hypothalamic hormones distinguishes it, key to understanding pituitary division, unlike hormone-generating glands.

Correct Answer: D

Rationale: The pituitary gland is purely endocrine, releasing hormones (e.g., GH, TSH) into blood, lacking exocrine ducts. The pancreas is dual endocrine islets (insulin) and exocrine acini (digestive enzymes). Kidneys are endocrine (erythropoietin, renin) and exocrine (urine via nephrons). Gonads (testes/ovaries) are endocrine (testosterone/estrogen) and exocrine (sperm/eggs via ducts). Pituitary's exclusive endocrine nature distinguishes it, key to its master gland status, unlike dual-function organs.