The difference between what two pressures drives air into and out of the lungs?

Question

Quizplus · Accepted Answer

The difference between atmospheric pressure (the pressure of the air outside the body) and intra-alveolar pressure (the pressure inside the lung alveoli) drives air into and out of the lungs. When intra-alveolar pressure is lower than atmospheric pressure, air flows into the lungs (inhalation). When intra-alveolar pressure is higher than atmospheric pressure, air flows out of the lungs (exhalation).

The Difference Between What Two Pressures Drives Air into and Out