Respiratory centre of brain is sensitive to

Options

A. more `CO_(2)` concentration in blood
B. more `O_(2)` concentration in blood
C. accumulation of blood in brain
D. all of the above

Answer

**Step-by-Step Solution:**

1. **Understanding the Respiratory Center**: The respiratory center is located in the brain, specifically in the medulla oblongata and pons. It plays a crucial role in regulating the rate and depth of breathing.

2. **Sensitivity to CO2 Levels**: The respiratory center is particularly sensitive to the concentration of carbon dioxide (CO2) in the blood. An increase in CO2 levels leads to an increase in the rate of respiration to expel more CO2.

3. **Sensitivity to O2 Levels**: While the respiratory center primarily responds to CO2 levels, it is also sensitive to low levels of oxygen (O2) in the blood. A decrease in O2 concentration can stimulate the respiratory center to increase breathing rate.

4. **Sensitivity to Blood Accumulation**: The respiratory center can also respond to changes in blood flow and pressure in the brain. Accumulation of blood can affect the overall function of the respiratory center.

5. **Conclusion**: Since the respiratory center is sensitive to all the mentioned factors—more CO2 concentration, low O2 concentration, and blood accumulation—the correct answer is option D: all of the above.

**Final Answer**: The respiratory center of the brain is sensitive to all of the above (Option D).

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