ANATOMY

Detailed explanation-1: -Distal Convoluted Tubule and Connecting Tubule The structure reflects the active transport function of these segments with luminal and basolateral surface area amplification and ample endowment of organelles (Figure 3.11).

Detailed explanation-2: -Following filtration, potassium is extensively reabsorbed along the proximal tubule and the loop of Henle. Potassium is secreted along the initial and cortical collecting tubule. Net secretion can be replaced by net reabsorption in states of potassium depletion.

Detailed explanation-3: -Tubular secretion is the transfer of materials from peritubular capillaries to the renal tubular lumen and occurs mainly by active transport. It is the tubular secretion of H+and NH4+ from the blood into the tubular fluid that helps to keep blood pH at its normal level.

Detailed explanation-4: -Renal Handling of Potassium Potassium is freely filtered at the glomerulus and passes through to the proximal convoluted tubule (PCT) and loop of Henle, where most of it is reabsorbed. There is some reabsorption in the distal convoluted tubule and collecting duct, but potassium secretion also occurs at these sites.