During inspiration ,

Options

A. The diaphragm gets raised and ribs get lowered
B. Both diaphragm and ribs get lowered
C. Ribs get raised and diaphragm get lowered
D. The diaphragm gets flattered and ribs get raised.

Answer

### Step-by-Step Solution:

1. **Understanding Inspiration**:
- Inspiration refers to the process of inhaling oxygen-rich air into the lungs. This is a vital part of the respiratory cycle.

2. **Role of Intercostal Muscles**:
- The intercostal muscles are located between the ribs. During inspiration, these muscles contract, which causes the ribs to move outward and upward.

3. **Diaphragm Movement**:
- The diaphragm, a dome-shaped muscle at the base of the thoracic cavity, also plays a crucial role. During inhalation, the diaphragm contracts and flattens, moving downward.

4. **Changes in Thoracic Cavity Volume**:
- As the intercostal muscles pull the ribs outward and the diaphragm flattens, the volume of the thoracic cavity increases.

5. **Pressure Changes**:
- According to Boyle's Law, when the volume of a container increases, the pressure inside decreases. Therefore, as the thoracic cavity volume increases, the pressure inside the lungs decreases.

6. **Air Flow into Lungs**:
- The decrease in pressure inside the lungs compared to the atmospheric pressure causes air to flow into the lungs, completing the process of inspiration.

7. **Correct Option Identification**:
- Based on the above phenomena, we analyze the options provided:
- Option 1: Diaphragm gets raised and ribs lowered - Incorrect.
- Option 2: Both diaphragm and ribs get lowered - Incorrect.
- Option 3: Ribs get raised and diaphragm get lowered - Incorrect.
- Option 4: Diaphragm gets flattened and ribs get raised - Correct.

### Final Answer:
During inspiration, the diaphragm gets flattened and the ribs get raised.

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