Which of the following changes tends to increase glomerular filtration rate (GFR)?

Correct Answer: C

Rationale: Increased glomerular capillary filtration coefficient (Kf) boosts GFR enhances filtration surface/permeability (e.g., Starling forces). Afferent resistance increase lowers flow drops GFR. Efferent resistance decrease reduces pressure lowers GFR. Capsular pressure increase opposes decreases GFR. Kf's enhancement distinguishes it, critical for filtration capacity, unlike resistance or pressure shifts.

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: A

Rationale: ADH makes the distal nephron (collecting duct) water-permeable inserts aquaporins (e.g., concentrates urine). Urea reabsorption is medullary ADH aids, not PCT. All nephron water increase overstates distal-specific. NaCl in descending limb is passive not ADH. Permeability change distinguishes it, critical for osmoregulation, unlike urea or broad errors.

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.