Question

Type II alveolar cells

A) allow rapid diffusion of gases through their thin membranes.
B) allow rapid diffusion of gases through their thin membranes, secrete a chemical known as surfactant, and are phagocytic.
C) secrete a chemical known as surfactant.
D) are phagocytic.
E) None of the statements are true.

Answer 1

Type II alveolar cells secrete a chemical known as surfactant.

Step-by-step explanation:

Type II alveolar cells are different from Type I alveolar cells as they do not cover as much surface area as Type I covers. Type II cells begin to develop at about 26 weeks' gestation, releasing a small amount of surfactant.

However, substantial amounts of surfactants are not secreted until about 35 weeks after conception - this is the main cause of the increased rates of infant respiratory distress syndrome, which significantly decreases above the age of 35 weeks. These types of cells are also capable in cellular division.