Which of the following is not a factor affecting sodium reabsorption?

Correct Answer: D

Rationale: ADH doesn't directly affect sodium reabsorption targets water via aquaporins (e.g., collecting duct). Increased GFR raises Na filtration reabsorption adjusts. Aldosterone boosts Na retention ENaC channels. Natriuretic hormone inhibits Na reabsorption e.g., ANP. ADH's water focus distinguishes it, key to osmolality, unlike GFR, hormonal Na regulators.

Correct Answer: C

Rationale: The myogenic mechanism is vessels' intrinsic constriction to high pressure autoregulates GFR (e.g., afferent stretch). Hormonal control (e.g., angiotensin) is extrinsic renin-driven. Sympathetic control uses nerves reduces GFR. Tubuloglomerular feedback is macula densa NaCl-based. Intrinsic response distinguishes it, key to vascular autoregulation, unlike extrinsic or feedback controls.

Correct Answer: D

Rationale: Glucose reabsorption from lumen to cell is secondary active transport SGLT uses Na gradient (e.g., PCT), energy-dependent. Passive transport lacks energy false. Downhill misaligns against gradient. No energy contradicts mechanism incorrect. Sodium-coupled active transport distinguishes it, critical for glucose recovery, unlike passive or energy-free errors.

Correct Answer: B

Rationale: Intracellular potassium is ~150 mM high vs. extracellular ~4 mM (e.g., Na /K -ATPase maintains). 125 mM is close understated. 3.5 mM is extracellular opposite. 50 mM underestimates gradient incorrect. High concentration distinguishes it, critical for membrane potential, unlike lower values.

Correct Answer: D

Rationale: Na absorption in ascending Loop is active in thick (Na /K /2Cl⁻ cotransport) and passive in thin (e.g., gradient-driven). All passive ignores thick's pump false. All active overstates thin incorrect. Reversed activity misaligns thick is active. Dual mechanism distinguishes it, critical for concentration gradient, unlike uniform or swapped errors.