Question

Which of the following structures in the kidney is primarily responsible for the reabsorption of water and solutes from the filtrate?

• A. Glomerulus.
• B. Bowman's capsule.
• C. Proximal convoluted tubule.
• D. Distal convoluted tubule.

Hint:

The proximal convoluted tubule is responsible for bulk reabsorption of water, nutrients, and ions, which is essential for maintaining homeostasis.

Answer 1

The Correct Option is C

Step 1: Function of the proximal convoluted tubule (PCT).
The proximal convoluted tubule (PCT) is the first segment of the nephron tubule where reabsorption occurs. It reabsorbs approximately 65-70\% of the water and solutes, including glucose, amino acids, sodium, and chloride ions, from the filtrate into the blood. Step 2: Explanation of other options.
Option (A): Glomerulus. Incorrect. The glomerulus is responsible for the filtration of blood, not reabsorption. Option (B): Bowman's capsule. Incorrect. Bowman's capsule collects the filtrate but does not participate in reabsorption. Option (D): Distal convoluted tubule. Incorrect. The distal convoluted tubule is involved in selective reabsorption and secretion, but the majority of reabsorption occurs in the proximal convoluted tubule. Step 3: Conclusion.
The proximal convoluted tubule is the primary site for the reabsorption of water and solutes from the filtrate. \[ \therefore \text{The correct answer is: Proximal convoluted tubule (PCT).} \]