The glucose started to appear in the urine before the transport maximum is reached because?

Correct Answer: A

Rationale: Glucose appears before Tmax due to nephron variation heterogeneous Tmax (e.g., some saturate early). Complete reabsorption holds below Tmax false here. Passive reabsorption isn't glucose active. Secretion doesn't apply glucose isn't secreted. Variation distinguishes it, key to splay phenomenon, unlike total or mechanism errors.

Correct Answer: A

Rationale: Thirst center activates with 10-15% plasma volume drop or 1-2% osmolarity rise sensitive triggers (e.g., hypothalamus). 1-2% volume or 10-15% osmolarity reverses thresholds incorrect. Thirst is result not stimulus. ADH is parallel not cause. Precise thresholds distinguish it, key to thirst drive, unlike reversed or effect-based options.

Correct Answer: C

Rationale: With ADH, water reabsorption in collecting duct is passive osmosis via aquaporins (e.g., medullary gradient). Active transport is Na not water. Cortical-only mislimits medullary too. All passive distinguishes it, key to ADH's osmotic drive, unlike active or partial errors.

Correct Answer: D

Rationale: Bone buffers in chronic metabolic acidosis releases CaCO₃ (e.g., weeks-long compensation). Phosphate is tubular less chronic. Proteins assist limited capacity. Bicarbonate depletes overwhelmed. Bone's role distinguishes it, key to chronic buffering, unlike acute or depleted systems.

Correct Answer: C

Rationale: Simultaneous respiratory (PCO₂ 68, high) and metabolic acidosis (HCO₃⁻ 13, low) match pH 6.90 severe drop (e.g., overdose hypoventilation, lactic acidosis). Uncompensated metabolic lacks PCO₂ rise partial. Uncompensated respiratory misses HCO₃⁻ drop sole. Renal compensation raises HCO₃⁻ not here. Dual acidosis distinguishes it, key to mixed disorder, unlike single or compensated states.