Atrial natriuretic hormone (ANH) will promote a(n) _______ in the excretion of sodium and water; thus ______ blood volume and blood pressure.

Correct Answer: C

Rationale: ANH increases Na /water excretion reduces blood volume/BP (e.g., heart stretch response). Decrease contradicts ANH is natriuretic. Increase/increasing raises volume opposite. Increase/decreasing aligns distinguishes it, key to BP regulation, unlike retention or mismatched effects.

Correct Answer: B

Rationale: Large intestine isn't excretory removes feces, not metabolic waste (e.g., defecation vs. excretion). Kidney excretes urine true. Liver processes urea excretory. Lungs expel COâ‚‚ excretory. Intestine's fecal role distinguishes it, key to excretion definition, unlike waste-excreting organs.

Correct Answer: A

Rationale: Sodium balance hinges on GFR (filtration rate) and Na reabsorption e.g., PCT (65%), aldosterone (distal). GFR/renin ties BP not direct Na . Na /K links aldosterone partial view. None denies control false. GFR/reabsorption synergy distinguishes it, critical for Na homeostasis, unlike partial or null options.

Correct Answer: C

Rationale: Countercurrent exchange concentrates urine Loop of Henle/vasa recta gradient (e.g., ~1200 mOsm medulla). Bicarbonate buffers pH not concentration. Renin-angiotensin regulates BP not urine osmolality. Densification isn't a term false. Countercurrent's gradient distinguishes it, key to urine concentration, unlike buffering or BP systems.

Correct Answer: C

Rationale: Collecting ducts set urine osmolality ADH aquaporins adjust (e.g., 50-1200 mOsm). Water secretion is false reabsorbed. Most reabsorption is PCT (~65%) not collecting. ADH increases permeability opposite. Osmolality control distinguishes it, critical for concentration, unlike secretion or misattributed roles.