When the urinary bladder becomes stretched, there's an increase in the frequency of action potentials traveling from?

Correct Answer: A

Rationale: Bladder stretch increases action potentials from bladder to sacral region afferent nerves signal fullness (e.g., micturition reflex). Parasympathetic is efferent response, not trigger. Somatic motor controls sphincter not stretch. Ascending paths inform brain secondary. Afferent signaling distinguishes it, key to reflex initiation, unlike efferent or higher pathways.

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.

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.