Which of the following volume is not included in
vital capacity

Options

A. ERV
B. TV
C. IRV
D. RV

Answer

To determine which volume is not included in the vital capacity, we first need to understand what vital capacity is and what volumes are included in it.

### Step-by-step Solution:

1. **Definition of Vital Capacity**:
- Vital capacity (VC) is defined as the maximum amount of air that can be expelled from the lungs after maximum inhalation. It is a measure of the functional capacity of the lungs.

2. **Components of Vital Capacity**:
- Vital capacity is the sum of three specific lung volumes:
- **Tidal Volume (TV)**: The amount of air inhaled or exhaled during normal breathing, typically around 500 ml.
- **Inspiratory Reserve Volume (IRV)**: The additional amount of air that can be inhaled after a normal inhalation, generally about 2000 ml.
- **Expiratory Reserve Volume (ERV)**: The additional amount of air that can be forcibly exhaled after a normal exhalation, usually around 1000 ml.

3. **Calculation of Vital Capacity**:
- The formula for vital capacity can be expressed as:
\[ VC = TV + IRV + ERV \]
- Substituting the average values:
\[ VC = 500 \, \text{ml} + 2000 \, \text{ml} + 1000 \, \text{ml} = 3500 \, \text{ml} \, (or \, 3.5 \, \text{liters}) \]
- This indicates that the vital capacity of a normal adult human typically ranges between 3 to 5 liters.

4. **Identifying the Excluded Volume**:
- The question asks which volume is **not** included in the vital capacity. The options typically include:
- Tidal Volume (TV)
- Inspiratory Reserve Volume (IRV)
- Expiratory Reserve Volume (ERV)
- Residual Volume (RV)
- Among these, **Residual Volume (RV)** is the volume of air that remains in the lungs after a forceful exhalation and is **not** included in the vital capacity.

5. **Conclusion**:
- Therefore, the volume that is not included in the vital capacity is **Residual Volume (RV)**.

### Final Answer:
The volume that is not included in vital capacity is **Residual Volume (RV)**.