The function of surfactant is to
A)phagocytize particulate matter that has eluded the respiratory defenses and reached the alveoli.
B)cause capillaries to adhere closely to the alveolar surfaces to promote gas exchange.
C)reduce the surface tension in the fluid coating alveolar surfaces to prevent alveolar collapse.
D)cause diffusion.
E)None of the answers are correct.

Question

Quizplus · Accepted Answer

Surfactant is a substance secreted by the epithelial cells of the alveoli that reduces the surface tension of the fluid lining the alveoli. This prevents the collapse of the alveoli during expiration and promotes the efficient exchange of gases.  Choice A is incorrect because phagocytosis is a function of alveolar macrophages, not surfactant. Choice B is incorrect because capillaries do not adhere to alveolar surfaces; instead, they are in close proximity to facilitate gas exchange via diffusion. Choice D is incorrect because diffusion is not the function of surfactant.

The Function of Surfactant Is to