Re-absorption occurs in which parts of the nephron?

• A. Bowman's capsule only
• B. Loop of Henle, distal convoluted tubule, and proximal convoluted tubule
• C. Collecting ducts only
• D. Ureter and bladder

Answer: (B)

Reabsorption is the process of reclaiming substances from the filtrate back into the bloodstream. The major nephron segments where this happens are the proximal convoluted tubule, the loop of Henle, and the distal convoluted tubule. In the proximal tubule, most filtered water, ions, glucose, and amino acids are reabsorbed. The loop of Henle reabsorbs water in the descending limb and Na+, K+, and Cl− in the ascending limb, helping concentrate the filtrate. The distal tubule continues reabsorbing Na+ and, under hormonal control, water. Bowman's capsule is the site of filtration, not reabsorption, so it isn’t the correct choice. Collecting ducts do reabsorb water under hormonal influence, but the option grouping that includes the proximal tubule, loop of Henle, and distal tubule best captures the main reabsorptive sites. Ureter and bladder do not reabsorb filtrate.