Which statement is correct ?

Options

A. Pulmonary ventilation is equal to alveolar ventilation
B. Pulmonary ventilation is less than alveolar ventilation
C. Alveolar ventilation is more than Pulmonary ventilation
D. Alveolar ventilation is less than Pulmonary ventilation

Answer

To determine which statement is correct regarding pulmonary ventilation and alveolar ventilation, we can follow these steps:

### Step-by-Step Solution:

1. **Define Pulmonary Ventilation**:
- Pulmonary ventilation refers to the total exchange of air between the lungs and the ambient air. It is the volume of air inhaled or exhaled from the lungs in a minute.
- For a normal adult, pulmonary ventilation is approximately 6.0 liters per minute.

2. **Define Alveolar Ventilation**:
- Alveolar ventilation is the portion of pulmonary ventilation that reaches the alveoli and is available for gas exchange. It accounts for the air that does not participate in gas exchange (such as dead space).
- For a normal adult, alveolar ventilation is approximately 4.2 liters per minute.

3. **Compare Pulmonary and Alveolar Ventilation**:
- Since pulmonary ventilation (6.0 L/min) is greater than alveolar ventilation (4.2 L/min), we can conclude that alveolar ventilation is less than pulmonary ventilation.

4. **Evaluate the Statements**:
- **Statement 1**: Pulmonary ventilation equals alveolar ventilation - This is incorrect.
- **Statement 2**: Pulmonary ventilation is less than alveolar ventilation - This is incorrect.
- **Statement 3**: Alveolar ventilation is more than pulmonary ventilation - This is incorrect.
- **Statement 4**: Alveolar ventilation is less than pulmonary ventilation - This is correct.

5. **Conclusion**:
- The correct statement is that alveolar ventilation is less than pulmonary ventilation.

### Final Answer:
The correct statement is: **Alveolar Ventilation is less than Pulmonary Ventilation (Option 4)**.

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