In the proximal tubule, sodium moves from the lumen into the tubule epithelial cell by diffusion through sodium channels.

Question

Quizplus · Accepted Answer

In the proximal tubule, sodium moves from the lumen into the tubule epithelial cell primarily through active transport mechanisms, not simply by diffusion through sodium channels. Sodium transport is coupled with the transport of other molecules like glucose and amino acids via cotransporters, and its reabsorption is energy-dependent, utilizing the sodium-potassium ATPase pump on the basolateral membrane.

In the Proximal Tubule, Sodium Moves from the Lumen into the Tubule