A symptom of diabetes mellitus is:

Correct Answer: B

Rationale: Polydipsia (excessive thirst) is a diabetes mellitus symptom, driven by hyperglycemia dehydrating cells, triggering thirst. 'Glyconemia' isn't a term hyperglycemia is correct, but not listed. Weight gain contrasts with typical loss from glucose wasting. Hypoglycemia isn't characteristic high glucose defines it. Polydipsia's link to osmotic diuresis distinguishes it, key to diabetes recognition, unlike misnamed or opposing signs.

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: The thyroid, anterior to the trachea and below the larynx, contains embedded parathyroids (posteriorly) and produces three hormones: thyroxine (T4), triiodothyronine (T3), and calcitonin. All statements hold: location aids surgical identification, parathyroids regulate calcium, and hormones manage metabolism/calcium. This comprehensive accuracy distinguishes thyroid anatomy/function, key to endocrine physiology.

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.