How does DCT maintain the pH and sodium-potassium balance in blood?

Distal Convoluted Tubule (DCT): Conditional reabsorption of Na⁺ and water takes place in this segment. DCT is also capable of reabsorption of HCO3– and selective secretion of hydrogen and potassium ions and NH₃ to maintain the pH and sodium-potassium balance in blood. Collecting Duct: This long duct extends from the cortex of the kidney to the inner parts of the medulla. Large amounts of water could be reabsorbed from this region to produce a concentrated urine. This segment allows passage of small amounts of urea into the medullary interstitium to keep up the osmolarity. It also plays a role in the maintenance of pH and ionic balance of blood by the selective secretion of H⁺ and K⁺ ions