Volume of air breathed in and out during normal breathing is called

Options

A. Tidal volume
B. Reserve volume
C. Residual volume
D. None of these

Answer

To answer the question about the volume of air breathed in and out during normal breathing, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Question**: The question asks for the term that describes the volume of air that is inhaled and exhaled during normal breathing.

2. **Identifying the Options**: The options provided are:
- Tidal volume
- Reserve volume
- Residual volume
- None of these

3. **Defining Residual Volume**:
- Residual volume is the amount of air that remains in the lungs after a forcible expiration. This volume cannot be expelled from the lungs and is not relevant to normal breathing.

4. **Defining Reserve Volume**:
- Reserve volume refers to the additional air that can be inhaled or exhaled beyond the normal tidal volume during forceful breathing. This is also not what the question is asking for.

5. **Defining Tidal Volume**:
- Tidal volume is the volume of air that is inhaled or exhaled during normal breathing. It is typically around 500 ml in a young adult human.

6. **Conclusion**: Based on the definitions, the correct answer to the question is **Tidal Volume**.

### Final Answer:
The volume of air breathed in and out during normal breathing is called **Tidal Volume**.

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