Which of the following is false about sodium reabsorption?

Correct Answer: C

Rationale: Sodium reabsorption in the proximal convoluted tubule (PCT) involves Na⁺ entering the cell from the lumen (A is true) via cotransporters, but it's transported out to the capillary via Na⁺/K⁺-ATPase, a primary active transport process, not passive (C is false). The pump uses ATP to move Na⁺ against its gradient, contradicting C, making it the false statement.

Correct Answer: C

Rationale: Effective evaluation feedback requires regular, specific communication about performance (C), enabling staff to understand strengths and areas for improvement, fostering growth. Weekly meetings (A) may help but aren't specific to feedback, delegation (B) is task assignment, and goal-setting (D) is planning, not evaluation, making C the key to effectiveness.

Correct Answer: B

Rationale: Tubular secretion actively transports substances (e.g., H⁺, K⁺, drugs) from peritubular capillaries into renal tubules (B), aiding waste elimination and pH balance. Reabsorption (A) retrieves substances, filtration (C) is glomerular, and blood pressure control (D) is indirect, making B the correct role.

Correct Answer: D

Rationale: Sympathetic stimulation (A) constricts the afferent arteriole, reducing GFR; obstruction (B) increases capsular pressure, lowering GFR; and efferent vasodilation (C) decreases glomerular pressure, reducing GFR. None increase GFR—sympathetic effects lower it, obstruction opposes filtration, and efferent dilation reduces driving force—making D (none are correct) the answer.

Correct Answer: C

Rationale: Within an hour, buffers (A), lungs (B), and hemoglobin (D) act, but kidneys can't fully eliminate nonvolatile acids or regenerate all bicarbonate (C) that fast—renal response takes hours to days. C is the exception, making it the answer.