The maximum volume of air a person can breathe in after a forced expiration is

Options

A. Vital capacity
B. ERV + TV + IRV
C. TLC - RV
D. All of these

Answer

To solve the question regarding the maximum volume of air a person can breathe in after a forced expiration, we can break it down step by step:

### Step-by-Step Solution:

1. **Understand the Terminology**:
- **Tidal Volume (TV)**: This is the normal amount of air that is inhaled or exhaled with each breath, which is approximately 500 ml.
- **Inspiratory Reserve Volume (IRV)**: This is the additional amount of air that can be inhaled after a normal inhalation.
- **Expiratory Reserve Volume (ERV)**: This is the additional amount of air that can be exhaled after a normal exhalation.
- **Residual Volume (RV)**: This is the amount of air remaining in the lungs after a forced expiration.

2. **Identify the Scenario**:
- The question asks for the maximum volume of air that can be breathed in after a forced expiration. This means we need to consider the air that can be inhaled after a person has exhaled as much as possible.

3. **Calculate the Maximum Inhalation**:
- After a forced expiration, the person will have expelled the tidal volume and the expiratory reserve volume.
- When the person inhales maximally after this forced expiration, they will take in:
- The tidal volume (TV)
- The inspiratory reserve volume (IRV)

4. **Combine the Volumes**:
- The total volume of air that can be breathed in after a forced expiration is the sum of the tidal volume (TV) and the inspiratory reserve volume (IRV):
\[ \text{Maximum Inhalation} = TV + IRV \]
- Since the residual volume (RV) is already present in the lungs and does not change with forced expiration or inspiration, it is not included in this calculation.

5. **Conclusion**:
- The maximum volume of air a person can breathe in after a forced expiration is equal to the tidal volume plus the inspiratory reserve volume.

### Final Answer:
The maximum volume of air a person can breathe in after a forced expiration is the sum of the tidal volume and the inspiratory reserve volume (TV + IRV).

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