ANATOMY

Detailed explanation-1: -Hence, the correct answer is ‘Potassium secretion in distal convoluted tubule’.

Detailed explanation-2: -The distal convoluted tubule also contains intercalated (I) cells, responsible for the secretion of acid. The collecting ducts are composed of I cells and also principal (P) cells, which become permeable to water under the influence of vasopressin.

Detailed explanation-3: -Potassium is secreted along the initial and cortical collecting tubule. Net secretion can be replaced by net reabsorption in states of potassium depletion. Also shown are the two cell types lining the distal tubule and cortical collecting duct.

Detailed explanation-4: -K+ secretion begins in the early distal convoluted tubule and progressively increases along the distal nephron into the cortical collecting duct (Figure 5).

Detailed explanation-5: -As fluid travels down the DCT, the luminal potassium concentration increases, indicating that net K+ secretion occurs along the distal tubule.