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: Proximal Convoluted Tubule (PCT) Function.
The PCT is the initial section of the nephron tubule responsible for reabsorption. It recovers approximately 65-70% of water and solutes, such as glucose, amino acids, sodium, and chloride ions, from the filtrate into the bloodstream. 

Step 2: Other Options Evaluated. 
Option (A): Glomerulus. Incorrect. The glomerulus filters blood; it does not reabsorb substances. 

Option (B): Bowman's capsule. Incorrect. Bowman's capsule gathers filtrate but plays no role in reabsorption. 

Option (D): Distal convoluted tubule. Incorrect. While the distal convoluted tubule performs selective reabsorption and secretion, the bulk of reabsorption occurs in the proximal convoluted tubule. 

Step 3: Final Determination. 
The proximal convoluted tubule serves as the main site for reabsorbing water and solutes from the filtrate. \[ \therefore \text{The correct answer is: Proximal convoluted tubule (PCT).} \]