The countercurrent flow of filtrate back up the nephron loop permits transport of large amounts of sodium and chloride into the interstitial fluid of the medulla.

Question

Quizplus · Accepted Answer

Countercurrent flow allows for a concentration gradient to be established in the medulla, which drives the reabsorption of sodium and chloride from the filtrate in the descending limb of the loop of Henle and into the interstitial fluid of the medulla in the ascending limb of the loop of Henle. This helps in the concentration of the urine.

The Countercurrent Flow of Filtrate Back Up the Nephron Loop