In man the osmotic centres are stimulated in

Options

A. Cerebrum
B. Hypothalamus
C. Pituitary gland
D. Medulla oblongata

Answer

**Step-by-Step Solution:**

1. **Understanding Osmotic Centers**: The question asks about the osmotic centers in humans, which are responsible for regulating osmotic balance in the body.

2. **Identifying Osmoreceptors**: Osmoreceptors are specialized cells that detect changes in the osmotic pressure of the extracellular fluid (ECF).

3. **Location of Osmoreceptors**: In humans, these osmoreceptors are primarily located in the hypothalamus, a region of the brain that plays a crucial role in homeostasis.

4. **Function of Osmoreceptors**: The osmoreceptors respond to changes in the concentration of sodium ions (Na+) in the ECF. They monitor the tonicity of the ECF, which is vital for maintaining fluid balance in the body.

5. **Conclusion**: Since the osmoreceptors are located in the hypothalamus and are responsible for monitoring osmotic changes, the osmotic centers in man are stimulated in the hypothalamus.

**Final Answer**: The osmotic centers in man are stimulated in the hypothalamus.

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