Physiology Pulmonary surfactant: A Increases the surface tension of the alveolar lining liquid B Is secreted by type I alveolar epithelial cells C Is a protein D Helps to prevent transudation of fluid from the capillaries into the alveolar spaces 💡 Explanation Pulmonary surfactant: ✓ Correct Answer: D. Helps to prevent transudation of fluid from the capillaries into the alveolar spaces