Question

How does tubular secretion help in maintaining ionic and acid-base balance in body fluids?

Answer 1

During urine formation, the tubular cells secrete substances like H⁺, K⁺ and ammonia into the filtrate. Tubular secretion is also an important step in urine formation as it helps in the maintenance of the ionic and acid-base balance of body fluids.

• PCT helps to maintain the pH and ionic balance of the body fluids by selective secretion of hydrogen ions, ammonia and potassium ions into the filtrate
• DCT is also capable of selective secretion of hydrogen and potassium ions and NH₃ to maintain the pH and sodium-potassium balance in the blood.
• The collecting duct also plays a role in the maintenance of pH and ionic balance of blood by the selective secretion of H⁺ and K⁺