The functional unit of the kidney is called ________.

Correct Answer: C

Rationale: Nephron is the functional unit not hilus (entry), corpuscle (part), or capsule (subset). This defines renal physiology, critical for function, contrasting with structural parts.

Correct Answer: A

Rationale: Ascending loop actively reabsorbs Na+ (Na+/K+/2Cl- pump) not Cl- alone, or passive K+/urea. This specifies diluting role, key for concentration gradient, contrasting with passive processes.

Correct Answer: D

Rationale: Kidney stones include calcium phosphate, oxalate, and uric acid not HCO3 (bicarbonate, soluble). This distinguishes stone composition, key for treatment, contrasting with non-stone solutes.

Correct Answer: D

Rationale: Kidneys span T12 to L3 not higher thoracic or extended lumbar. This specifies position, vital for radiology, contrasting with incorrect spans.

Correct Answer: C

Rationale: The distal convoluted tubule excels in secretion lacks microvilli (reabsorption-focused), emphasizing secretion (e.g., H , K ) via active transport. The proximal tubule dominates reabsorption ~65% of filtrate (e.g., glucose, Na ) but secretes organics (e.g., creatinine). The Loop of Henle focuses on concentration minimal secretion. The collecting duct adjusts urine via reabsorption/secretion (e.g., H by intercalated cells) less secretion-centric. The distal tubule's secretion role, tied to fine-tuning ion balance, distinguishes it, critical for acid-base and potassium regulation, unlike reabsorption-heavy or concentration-focused segments.