The duration of inhalation is shortened by signals from

Options

A. pneumotaxic area
B. apneustic area
C. inspiratory area
D. expiratory area

Answer

To solve the question regarding which area shortens the duration of inhalation, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Question**: The question asks which area is responsible for shortening the duration of inhalation.

2. **Identify the Options**: The options provided are:
- A) Pneumotoxic area
- B) Apneustic area
- C) Inspiratory area
- D) Expiratory area

3. **Analyze Each Option**:
- **Option A: Pneumotoxic Area**: This area is located in the pons and is known to send inhibitory signals to the inspiratory neurons. This means it can shorten the duration of inhalation by stopping the inspiratory process.
- **Option B: Apneustic Area**: This area also resides in the pons but primarily acts to prolong inhalation by stimulating the inspiratory neurons, thus it does not shorten inhalation.
- **Option C: Inspiratory Area**: This area refers to the dorsal respiratory group which is primarily responsible for initiating inhalation, not shortening it.
- **Option D: Expiratory Area**: Also known as the ventral respiratory group (VRG), this area is involved in expiration and does not play a role in shortening inhalation.

4. **Conclusion**: Based on the analysis, the pneumotoxic area (Option A) is responsible for sending signals that shorten the duration of inhalation.

### Final Answer:
The duration of inhalation is shortened by signals from the **pneumotoxic area** (Option A).

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