8-15% of water reabsorbed in the distal convoluted tubule needs?

Correct Answer: B

Rationale: 8-15% water reabsorption in the distal tubule requires ADH inserts aquaporins (e.g., facultative reabsorption). Aldosterone targets Na indirect water. Angiotensin II constricts GFR effect. Combined misaligns ADH drives water. ADH's role distinguishes it, critical for distal water control, unlike sodium or vascular factors.

Correct Answer: C

Rationale: With ADH, medullary osmolality reaches 1200 mOsm/kg NaCl (countercurrent) and urea (recycling) contribute (e.g., concentrated urine). NaCl alone understates urea adds. Urea alone ignores NaCl insufficient. Never reaching 1200 denies physiology false. Dual solutes distinguish it, critical for concentration, unlike single or negated factors.

Correct Answer: B

Rationale: COâ‚‚ excretion by lungs is fastest seconds to alter pH (e.g., hyperventilation). Kidney H excretion takes hours slow. Buffers act instantly chemical, not system. Protein binding assists secondary. Lung speed distinguishes it, critical for acute control, unlike renal or buffer pace.

Correct Answer: C

Rationale: Metabolic alkalosis fits pH 7.55 (high), HCO₃⁻ 40 (elevated), PCO₂ 52 (compensatory rise) from GI H loss (e.g., vomiting). Metabolic acidosis lowers pH/HCO₃⁻ opposite. Respiratory alkalosis drops PCO₂ unmatched. Respiratory acidosis raises PCO₂/lowers pH misfit. HCO₃⁻ elevation distinguishes it, critical for alkalosis diagnosis, unlike acidotic or respiratory shifts.

Correct Answer: C

Rationale: Bowman's capsule encases the glomerulus not ureter (transport), loop of Henle (medulla), or bladder (storage). This specifies filtration anatomy, key for understanding GFR, contrasting with distant structures.