How does the intrapleural pressure change during a normal, quiet breath?

Explanation

### Step-by-Step Solution:

1. **Understanding Breathing Mechanics**: Breathing involves the movement of air into and out of the lungs, which is facilitated by pressure changes within the respiratory system.

2. **Intrapleural Pressure Definition**: Intrapleural pressure is the pressure within the pleural cavity, the space between the lungs and the chest wall. It is typically negative relative to atmospheric pressure.

3. **Phases of Breathing**: During a normal, quiet breath, there are two main phases: inhalation (inspiration) and exhalation (expiration).

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