The walls of the alveoli are composed of two types of cells, type I and type II. The function of type II is to .
A) replace mucus in the alveoli
B) trap dust and other debris
C) protect the lungs from bacterial invasion
D) secrete surfactant

Question

Quizplus · Accepted Answer

Type II alveolar cells secrete surfactant, which reduces surface tension in the alveoli and prevents their collapse, aiding in efficient gas exchange.

The Walls of the Alveoli Are Composed of Two Types