Control of sodium

Approximately what percentage of filtered sodium (Na⁺) is reabsorbed in the proximal convoluted tubule (PCT) of the nephron?

65%

Approximately what percentage of filtered sodium (Na⁺) is reabsorbed in the loop of Henle, primarily in the thick ascending limb?

25%

Approximately what percentage of filtered sodium (Na⁺) is reabsorbed in the distal tubule, including both the distal convoluted tubule and connecting segments, under typical physiological conditions?

9%

Approximately what percentage of filtered sodium (Na⁺) is reabsorbed in the medullary collecting duct of the nephron?

1–3%

Which of the following ions are transported by the triple cotransporter (NKCC2) in the thick ascending limb of the loop of Henle?

Na⁺, K⁺, Cl⁻

Thiazide diuretics primarily act on which part of the nephron?

Distal convoluted tubule

Amiloride, a potassium-sparing diuretic, acts on which specific part of the nephron?

Collecting duct (principal cells)

Furosemide, a potent loop diuretic, primarily acts on which part of the nephron?

Thick ascending limb of the loop of Henle

Spironolactone primarily acts on which part of the nephron?

Collecting duct (principal cells)

What is the primary action of spironolactone in the nephron?

Blocks aldosterone receptors in the collecting duct, reducing sodium reabsorption

What is the primary role of macula densa cells in the nephron?

Detect sodium chloride concentration in the distal tubule and regulate renin release