Define the rate of ventilation.

Explanation

**Step-by-Step Text Solution:**

1. **Understanding Ventilation**: Ventilation refers to the process of inhaling (taking in air) and exhaling (breathing out air). It is a vital part of the respiratory system.

2. **Defining Rate of Ventilation**: The rate of ventilation is defined as the volume of air that is inhaled and exhaled in a specific period, typically measured in one minute.

3. **Measurement**: The rate of ventilation can be quantified in terms of the volume of air breathed per minute. This is important for understanding how efficiently the respiratory system is functioning.

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