Residual volume is

Options

A. Lesser than tidal volume
B. Greater than inspiratory volume
C. Greater than vital capacity
D. Greater than tidal volume

Answer

**Step-by-Step Solution:**

1. **Understanding Residual Volume**:
- Residual volume (RV) is defined as the amount of air that remains in the lungs after the most forcible expiration. This volume is crucial as it prevents the collapse of the lungs.

2. **Quantifying Residual Volume**:
- The typical value for residual volume is approximately 1100 to 1200 ml. This means that even after exhaling as much air as possible, this amount of air will still remain in the lungs.

3. **Comparing Residual Volume with Other Lung Volumes**:
- **Tidal Volume (TV)**: This is the amount of air inhaled or exhaled with each breath, which is about 500 ml.
- **Inspiratory Reserve Volume (IRV)**: This is the additional air that can be inhaled after a normal inhalation, typically around 2500 to 3000 ml.
- **Vital Capacity (VC)**: This is the total amount of air that can be exhaled after a maximum inhalation, which includes tidal volume, inspiratory reserve volume, and residual volume.

4. **Analyzing the Options**:
- **Option 1**: Residual volume is lesser than tidal volume. (Incorrect, as RV is 1100-1200 ml and TV is 500 ml)
- **Option 2**: Residual volume is greater than inspiratory volume. (Incorrect, as RV is less than IRV which is 2500-3000 ml)
- **Option 3**: Residual volume is greater than vital capacity. (Incorrect, as RV cannot exceed VC)
- **Option 4**: Residual volume is greater than tidal volume. (Correct, as RV is 1100-1200 ml which is greater than TV of 500 ml)

5. **Conclusion**:
- The correct answer is that the residual volume is greater than the tidal volume.

**Final Answer**: Residual volume is greater than tidal volume.

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