During inhalation diaphragm

Options

A. becomes dome shaped
B. becomes flat
C. remain unchanged
D. expands

Answer

**Step-by-Step Solution:**

1. **Understanding Inhalation**: Inhalation is the process where air is drawn into the lungs. This occurs due to changes in the volume of the thoracic cavity.

2. **Role of the Diaphragm**: The diaphragm is a dome-shaped muscle located at the base of the thoracic cavity. During inhalation, the diaphragm plays a crucial role in increasing the volume of the thoracic cavity.

3. **Muscle Actions**: During inhalation:
- The external intercostal muscles contract, which elevates the rib cage.
- The internal intercostal muscles relax.

4. **Diaphragm Movement**: As the diaphragm contracts, it moves downwards and flattens. This flattening increases the volume of the thoracic cavity.

5. **Creation of Vacuum**: The increase in volume leads to a decrease in pressure within the thoracic cavity, creating a vacuum. This vacuum pulls air into the lungs.

6. **Conclusion**: Therefore, during inhalation, the diaphragm becomes flat as it contracts.

**Final Answer**: During inhalation, the diaphragm becomes flat.

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