Which statement is correct regarding reabsorption in the nephron?

• A. Reabsorption only occurs in the collecting duct.
• B. Reabsorption is a process that removes substances from the blood and adds them to the filtrate.
• C. Most reabsorption of water and solutes occurs in the proximal convoluted tubule.
• D. Reabsorption is not influenced by hormones.

Answer: (C)

Verified step by step guidance

1. Step 1: Understand the concept of reabsorption in the nephron. Reabsorption is the process by which substances in the filtrate are moved back into the blood from the nephron tubules. This is essential for maintaining homeostasis and conserving important substances like water, glucose, and ions.
2. Step 2: Identify the primary site of reabsorption in the nephron. The proximal convoluted tubule is responsible for the majority of reabsorption, including water, glucose, amino acids, and ions such as sodium and chloride.
3. Step 3: Clarify the role of hormones in reabsorption. Hormones like antidiuretic hormone (ADH) and aldosterone influence reabsorption in specific parts of the nephron, such as the distal convoluted tubule and collecting duct, to regulate water and electrolyte balance.
4. Step 4: Evaluate the incorrect statements. Reabsorption does not only occur in the collecting duct; it occurs throughout the nephron, with the proximal convoluted tubule being the most active site. Additionally, reabsorption moves substances from the filtrate back into the blood, not the other way around.
5. Step 5: Confirm the correct statement. Based on the physiological processes of the nephron, the correct statement is: 'Most reabsorption of water and solutes occurs in the proximal convoluted tubule.' This aligns with the function of the nephron in maintaining homeostasis.