At the glomerulus, bicarbonate ions are filtered out of the blood and renal tubules release hydrogen cations into the tubule fluid. Here, the filtered bicarbonate neutralizes the hydrogen ions and maintains a moderate urine acidity. The carbon dioxide product is converted back to bicarbonate by the renal tubule cells and is redelivered into the interstitial fluid. In addition, the renal tube cells also filter out ammonia, which aids in acid-base balance.
Work Step by Step