When blood supply to the kidneys drops, the kidneys will release

Correct Answer: D

Rationale: Low blood supply triggers renin release JGA senses pressure drop (e.g., activates RAAS). Aldosterone is adrenal not kidney-produced. ANH from heart opposes retention. Water isn't released reabsorbed. Renin's response distinguishes it, key to restoring perfusion, unlike hormones or fluid missteps.

Correct Answer: A

Rationale: Formed elements (RBCs, WBCs, platelets) and plasma proteins (e.g., albumin) can't filter too large for glomerular barrier. Glucose filters reabsorbed later. Salts filter freely small ions. Formed elements/glucose mispairs glucose filters. Proteins/salts mix filterable/non-filterable wrong. Size exclusion distinguishes it, key to filtration selectivity, unlike mixed options.

Correct Answer: B

Rationale: Water intake is fluid ingested (drinking), food ingested (e.g., fruits), metabolic processes (e.g., oxidation ~300 mL/day). Air inhaled adds minimal water negligible. Excluding food ignores solids wrong. Excluding metabolism omits internal false. Triple mechanism distinguishes it, key to hydration sources, unlike incomplete sets.

Correct Answer: B

Rationale: ADH decreases urine production inserts aquaporins, reabsorbs water (e.g., concentrated urine). Increased production opposes diuresis. No change ignores ADH false. Dilute misaligns ADH concentrates. Reduced output distinguishes it, critical for osmoregulation, unlike diuresis or neutral effects.

Correct Answer: C

Rationale: Carbonic acid (H₂CO₃) and bicarbonate (HCO₃⁻) are the key blood buffer e.g., H₂CO₃ ↔ H + HCO₃⁻ (H-H equation). Water alone doesn't buffer neutral. CO₂/HCO₃⁻ lacks acid form partial. HCO₃⁻/water omits dynamic weak. H₂CO₃/HCO₃⁻ pair distinguishes it, critical for pH control, unlike incomplete sets.