Which of the following is true about tubular reabsorption in the nephron?

• A. It is responsible for the filtration of blood.
• B. It occurs exclusively in the collecting duct.
• C. It primarily occurs in the glomerulus.
• D. It involves the movement of substances from the tubular fluid back into the blood.

Answer: (D)

Verified step by step guidance

1. Understand the function of tubular reabsorption: Tubular reabsorption is a process in the nephron where substances are moved from the tubular fluid back into the blood. This is crucial for reclaiming water, ions, and nutrients that the body needs.
2. Identify the location of tubular reabsorption: Tubular reabsorption primarily occurs in the proximal convoluted tubule, but it also takes place in other parts of the nephron such as the loop of Henle, distal convoluted tubule, and collecting duct.
3. Differentiate between filtration and reabsorption: Filtration occurs in the glomerulus, where blood plasma is filtered into the nephron. Reabsorption, on the other hand, is the process of moving substances from the nephron back into the bloodstream.
4. Clarify the role of the collecting duct: While some reabsorption occurs in the collecting duct, it is not exclusive to this part of the nephron. The collecting duct primarily concentrates urine by reabsorbing water.
5. Conclude with the correct statement: The correct statement about tubular reabsorption is that it involves the movement of substances from the tubular fluid back into the blood, ensuring essential materials are retained by the body.