Final answer:
The pressure in the airway (Pa) decreases below atmospheric pressure during inhalation and increases above atmospheric pressure during exhalation.
Step-by-step explanation:
The pressure in the airway (Pa) changes during inhalation and exhalation. During inhalation, the pressure in the airway decreases below atmospheric pressure, creating a negative gauge pressure. This decrease in pressure helps to draw air into the lungs. On the other hand, during exhalation, the pressure in the airway increases above atmospheric pressure, resulting in a positive gauge pressure. This increase in pressure helps to push air out of the lungs.