500 ml respiratory volume in a normal adult human is related to

Options

A. Residual volume
B. Total lung capacity
C. Respiratory reserve volume
D. Tidal volume

Explanation

To determine the relationship of the 500 ml respiratory volume in a normal adult human, we need to analyze the options provided: residual volume, total lung capacity, respiratory reserve volume, and tidal volume.

### Step-by-Step Solution:

1. **Understanding Residual Volume**:
- Residual volume is the amount of air that remains in the lungs after a forceful expiration. This volume cannot be measured directly and is typically around 1.2 liters in an adult.
- **Hint**: Think about what happens to air in the lungs after you exhale forcefully.

2. **Understanding Total Lung Capacity**:
- Total lung capacity is the maximum amount of air the lungs can hold, which includes all volumes (tidal volume, inspiratory reserve volume, expiratory reserve volume, and residual volume). This is generally around 6 liters in adults.
- **Hint**: Consider how much air your lungs can hold at maximum capacity.

3. **Understanding Respiratory Reserve Volume**:
- Respiratory reserve volume refers to the additional amount of air that can be inhaled after a normal inhalation. This volume varies but is not typically around 500 ml.
- **Hint**: Think about how much extra air you can breathe in after a normal breath.

4. **Understanding Tidal Volume**:
- Tidal volume is the amount of air that is inhaled or exhaled during normal breathing. For a typical adult at rest, the tidal volume is approximately 500 ml.
- **Hint**: This is the volume of air you breathe in and out with each normal breath.

5. **Conclusion**:
- Since the question asks about the 500 ml respiratory volume in a normal adult human, the correct answer is **tidal volume**.
- Therefore, the answer is option **D: Tidal Volume**.

### Summary of the Solution:
The 500 ml respiratory volume in a normal adult human is related to **tidal volume**.