During inspiration the diaphragm

Options

A. relaxes to become dome shaped
B. contracts and flattens
C. shows no change
D. expands

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks about the state of the diaphragm during the process of inspiration, which is the phase of breathing where air enters the lungs.

2. **Breathing Process Overview**: Breathing consists of two main phases:
- **Inspiration**: Air is drawn into the lungs.
- **Expiration**: Air is expelled from the lungs.

3. **Role of the Diaphragm**: The diaphragm is a crucial muscle located below the lungs that plays a significant role in respiration.

4. **Intrapulmonary Pressure**: During inspiration, the pressure inside the lungs (intrapulmonary pressure) decreases relative to atmospheric pressure, allowing air to flow into the lungs.

5. **Diaphragm Movement During Inspiration**:
- When we inhale, the diaphragm contracts and moves downwards.
- This contraction causes the diaphragm to flatten, which increases the volume of the chest cavity and decreases the pressure inside the lungs, facilitating air intake.

6. **Conclusion**: Therefore, during inspiration, the diaphragm becomes contracted and flattens.

7. **Evaluating Options**:
- **Option A**: "Relaxes to become dome shape" - Incorrect, as this describes expiration.
- **Option B**: "Contracts and flattens" - Correct, as this describes the diaphragm during inspiration.
- **Option C**: "No change" - Incorrect, as there is a significant change in the diaphragm's shape.
- **Option D**: "Expand" - Incorrect, as the diaphragm does not expand but flattens.

8. **Final Answer**: The correct answer is **Option B: Contracts and flattens**.

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