The nephron, segment by segment

Key points

1. Proximal tubule: reabsorbs about two-thirds of filtered sodium and water and nearly all glucose and amino acids.
2. Thick ascending limb: Na⁺/K⁺/2Cl⁻ cotransporter, blocked by loop diuretics.
3. Distal convoluted tubule: Na⁺/Cl⁻ cotransporter, blocked by thiazides; PTH increases calcium reabsorption here.
4. Collecting duct: ENaC channels regulated by aldosterone, blocked by amiloride; spironolactone blocks the aldosterone receptor.
5. ADH inserts aquaporin-2 channels in principal cells to concentrate the urine.

The recorded lesson is in production. The preview plays the key points; the outline is below.

Lesson outline

1. 00:00 Filtration and the glomerulus
2. 02:30 Proximal tubule and carbonic anhydrase
3. 05:00 Loop of Henle and the countercurrent multiplier
4. 08:00 Distal tubule, calcium and thiazides
5. 10:30 Collecting duct, aldosterone and ADH
6. 13:00 Diuretics side by side