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a detergent-like agent that reduces the surface tension of the liquid film covering the inner lining of the pulmonary alveoli. As an alveolus becomes smaller during expiration, the surfactant becomes more concentrated, further reducing the surface tension and preventing alveolar collapse.
surfactant(sur-fak'tant) [ surf(ace)-act(ive) a(ge)nt]
A surface-active agent that lowers surface tension (e.g., oils and various forms of detergents). Artificial surfactants may be given endotracheally to relieve respiratory distress.
lung surfactantPulmonary surfactant.
modified natural surfactant
A replacement phospholipid from a natural source with some components removed.
A lipoprotein secreted by type II alveolar cells that decreases the surface tension of the fluid lining the alveoli, permitting expansion. Synthetic lung surfactant is available for treating patients with respiratory distress syndrome. In obstetrics, fetal production of surfactant can be stimulated by administration of a glucocorticoid 24 to 48 hr before an inevitable preterm birth.Synonym: lung surfactant See: betamethasone; lecithin-sphingomyelin ratio