Pulmonary surfactant is secreted by Type II alveolar cells and is a combination of lipids and proteins. Its main function is to decrease surface tension of the fluid lining the alveoli, which helps to prevent alveolar collapse during expiration and facilitate lung expansion during inspiration. By decreasing surface tension, surfactant also helps to resist elastic recoil of the lungs.

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Pulmonary Surfactant

Question 24

Multiple Choice

Pulmonary surfactant

A) is secreted by Type II alveolar cells
B) decreases surface tension of the fluid lining the alveoli
C) resists elastic recoil of the lungs
D) is a combination of lipids and proteins
E) all of these

Correct Answer: