ADH acts on

Options

A. Loop of Henle
B. Collecting tubule
C. Vasa efferentia
D. Vasa deferentia.

Answer

**Step-by-Step Solution:**

1. **Understanding ADH**: ADH stands for Antidiuretic Hormone, which is crucial for regulating water balance in the body. It is produced in the hypothalamus and stored in the pituitary gland.

2. **Function of ADH**: The primary function of ADH is to control the amount of water reabsorbed by the kidneys. It helps the body retain water and concentrate urine, thus preventing excessive water loss.

3. **Target of ADH**: ADH specifically acts on the collecting ducts and distal convoluted tubules of the nephron. These are parts of the kidney where water reabsorption occurs.

4. **Evaluating the Options**:
- **Option 1: Loop of Henle**: While it plays a role in water and sodium recovery, it is not the primary target of ADH.
- **Option 2: Collecting Tubule**: This is the correct answer as ADH acts here to increase water reabsorption.
- **Option 3: Vasa Efferentia**: This structure is involved in the transport of sperm, not in the action of ADH.
- **Option 4: Vasa Differentia**: Similar to Vasa Efferentia, this also relates to sperm transport and is not affected by ADH.

5. **Conclusion**: Based on the functions and target areas of ADH, the correct answer is that ADH acts on the collecting tubule.

**Final Answer**: ADH acts on the collecting tubule (Option 2).

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