Class 11 NEET Biology Excretory Products and Their Elimination

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 ionic and acid base balance of body fluids.
PCT ⟶ Selective secretion of H+, ammonia and K+into the filtrate.
DCT ⟶ Capable of reabsorption of HCO3−and selective secretion of H+,K+and NH3.