In the absence of pulmonary surfactant, smaller alveoli display a larger inward-directed pressure than do larger alveoli.

Question

Quizplus · Accepted Answer

This is true because pulmonary surfactant helps to reduce surface tension in the smaller alveoli, allowing them to stay open and reducing the inward-directed pressure. Without surfactant, the smaller alveoli will collapse, increasing the pressure gradient and making it harder for air to enter. Larger alveoli have less surface tension and can resist collapse, so they have a lower inward-directed pressure.

In the Absence of Pulmonary Surfactant, Smaller Alveoli Display a Larger