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 less than Pulmonary ventilation
D. Alveolar ventilation is less than Pulmonary ventilation

Answer

To solve the question "Which statement is correct?" regarding pulmonary and alveolar ventilation, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Definitions**:
- **Pulmonary Ventilation**: This refers to the total volume of air that is exchanged between the lungs and the ambient air per minute. In a normal adult, this is approximately 6 liters per minute.
- **Alveolar Ventilation**: This is the portion of the pulmonary ventilation that actually reaches the alveoli and is available for gas exchange with the blood. In a normal adult, this is about 4.2 liters per minute.

2. **Compare the Two Ventilation Types**:
- Since pulmonary ventilation (6 liters/min) is the total air exchanged and alveolar ventilation (4.2 liters/min) is the air that reaches the alveoli, we can see that pulmonary ventilation is greater than alveolar ventilation.

3. **Evaluate the Statements**:
- The statements provided are:
1. Pulmonary ventilation is equal to alveolar ventilation.
2. Pulmonary ventilation is less than alveolar ventilation.
3. Alveolar ventilation is less than pulmonary ventilation.
4. (Duplicate) Alveolar ventilation is less than pulmonary ventilation.
- Based on our comparison, the correct statement is that "Alveolar ventilation is less than pulmonary ventilation."

4. **Select the Correct Answer**:
- Therefore, the correct answer is that alveolar ventilation is less than pulmonary ventilation.

### Final Answer:
The correct statement is: **Alveolar ventilation is less than pulmonary ventilation.**

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