What characterizes denervation of both afferent and efferent supply to the urinary bladder?

Correct Answer: B

Rationale: Afferent/efferent denervation (e.g., cauda equina injury) causes a hypertonic, spasmatic bladder intrinsic smooth muscle overacts, periodic uncontrolled micturition. Sensation loss alone is afferent tonic. Normal reflex needs nerves false. Increased sensation contradicts denervation. Hypertonicity distinguishes it, key to dual nerve loss, unlike single or intact scenarios.

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: 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.