Question

In which portion of the nephron are glucose and amino acids reabsorbed?

-descending limb of the loop of Henle
-ascending limb of the loop of Henle
-distal tubule
-proximal tubule

Answer 1

Glucose and amino acids are reabsorbed in the proximal tubule of the nephron, where about two-thirds of the filtered substances are reabsorbed into the bloodstream.

So, the correct answer is option 4.

Step-by-step explanation:

Glucose and amino acids are reabsorbed primarily in the proximal convoluted tubule (PCT) of the nephron. The PCT is the first segment of the renal tubule following Bowman's capsule, and it is responsible for the reabsorption of a significant amount of solutes and water from the filtered blood that passes into the renal tubule.

Notably, about two-thirds of the filtered salts and water and all of the filtered organic solutes, which include glucose and amino acids, are reabsorbed here. These substances are transported from the renal tubular lumen back into the bloodstream through peritubular capillaries.

The PCT's epithelial cells contain microvilli that increase the surface area for reabsorption to occur efficiently. In contrast, other segments of the nephron, such as the loop of Henle and the distal convoluted tubule, play different roles mainly involving the reabsorption of ions and water to regulate urine concentration and volume.

So, the correct answer is option 4.