Which of the following centre can alter the duration of inspiration or thereby respiratory rate?

Options

A. Dorsal respiratory centre
B. Inspiratory centre
C. Pneumotaxic centre
D. Expiratory centre

Answer

To solve the question "Which of the following center can alter the duration of inspiration or thereby respiratory rate?", we will analyze each option provided.

### Step-by-Step Solution:

1. **Understanding the Question**: The question is asking for a specific center in the brain that can modify how long we breathe in (inspiration) and consequently affect the rate of breathing (respiratory rate).

2. **Evaluating the Options**:
- **Option 1: Dorsal Respiratory Center**:
- This center is located in the medulla oblongata and primarily controls the rhythm of breathing by receiving input from peripheral chemoreceptors. However, it does not significantly alter the duration of inspiration or respiratory rate.
- **Conclusion**: This option is incorrect.

- **Option 2: Respiratory Center**:
- This term generally refers to the medulla oblongata and pons, which regulate breathing patterns. However, it does not specifically alter the duration of inspiration.
- **Conclusion**: This option is also incorrect.

- **Option 3: Pneumotaxic Center**:
- The pneumotaxic center is located in the pons and plays a crucial role in regulating the rate and pattern of breathing. It can indeed alter the duration of inspiration, thereby affecting the respiratory rate.
- **Conclusion**: This option is correct.

- **Option 4: Expiratory Center**:
- This center is also located in the medulla oblongata and primarily controls the process of expiration (breathing out). It does not play a significant role in altering the duration of inspiration.
- **Conclusion**: This option is incorrect.

3. **Final Answer**: Based on the analysis, the correct answer is **Option 3: Pneumotaxic Center**.