Absorption of water in DCT is controlled by

Options

A. ACTH
B. ADH
C. LH
D. Oxytocin

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks about the regulation of water absorption in the distal convoluted tubule (DCT) of the nephron in the kidneys.

2. **Identifying the Key Hormone**: The primary hormone responsible for controlling water absorption in the DCT is the Anti-Diuretic Hormone (ADH), also known as vasopressin.

3. **Function of ADH**: ADH is secreted by the posterior pituitary gland in response to dehydration or increased plasma osmolality. Its main function is to promote water reabsorption in the kidneys.

4. **Mechanism of Action**: When ADH is released, it acts on the cells of the DCT and collecting ducts, increasing their permeability to water. This allows more water to be reabsorbed back into the bloodstream, thus concentrating the urine.

5. **Impact on Urine Concentration**: As a result of increased water reabsorption due to ADH, the urine becomes more concentrated, meaning less water is lost from the body.

6. **Evaluating Other Options**:
- **ACTH (Adrenocorticotropic Hormone)**: This hormone stimulates the adrenal glands to release cortisol and does not directly control water absorption.
- **LH (Luteinizing Hormone)**: This hormone is involved in the reproductive system and does not play a role in water absorption.
- **Oxytocin**: This hormone is primarily involved in childbirth and lactation, not in water regulation.

7. **Conclusion**: The correct answer to the question is ADH, as it is the hormone that controls the absorption of water in the DCT.

**Final Answer**: The absorption of water in the DCT is controlled by ADH (Anti-Diuretic Hormone).

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