Excretory Organs and Their Functions — NEET Biology

Which of the above statements are correct regarding tubular secretion? S1: Tubular cells in different segments of the nephron actively secrete substances such as H+, K+, and ammonia into the filtrate. S2: The selective secretion of H+ and K+ ions by the collecting duct is important for regulating the pH and ionic balance of blood. S3: Reabsorption of all essential nutrients like glucose and amino acids occurs exclusively through active secretion by tubular cells. S4: Urea is primarily reabsorbed by the collecting duct into the medullary interstitium via active transport to maintain osmolarity. S5: Tubular secretion is an important step in urine formation as it helps in the maintenance of ionic and acid-base balance of body fluids.