Respiratory process is regulated by certain specialised centres in the brain. One of the following listed centres can reduce the inspiratory duration upon stimulation.

Options

A. Medullary inspiratory centre
B. Pneumotaxic centre
C. Apneustic centre
D. Chemosensitive centre

Explanation

To solve the question regarding which specialized center in the brain can reduce the inspiratory duration upon stimulation, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Respiratory Process**:
- The respiratory process is controlled by specialized centers in the brain that regulate breathing patterns, including the duration of inspiration (the intake of air).

2. **Identifying the Centers**:
- The question lists four centers:
- Medullary inspiratory center
- Pneumotoxic center
- Apneustic center
- Chemosensitive center

3. **Function of Each Center**:
- **Medullary Inspiratory Center**: Primarily responsible for initiating inspiration.
- **Pneumotoxic Center**: Located in the pons, this center regulates the rate and pattern of breathing. It specifically reduces the duration of inspiration when stimulated.
- **Apneustic Center**: Promotes prolonged inspiration and can increase the duration of inhalation.
- **Chemosensitive Center**: Responds to changes in blood chemistry (like CO2 levels) but does not directly control the duration of inspiration.

4. **Determining the Correct Answer**:
- Since the question specifically asks for the center that reduces the inspiratory duration, the pneumotoxic center is the correct choice. It acts as a "switch off" point for inspiration, effectively shortening the time spent inhaling.

5. **Conclusion**:
- Therefore, the answer to the question is the **Pneumotoxic Center** (Option 2).

### Final Answer:
The center that can reduce the inspiratory duration upon stimulation is the **Pneumotoxic Center**.

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