ABSTRACT
Pulmonary surfactant (‘‘surface active agent’’) is a complex mixture of
lipids and proteins, which is secreted by type II cells into the alveolar space of all mammalian lungs (1). Its main function is to lower the surface tension
at the air-water interface and thereby promote lung expansion during
inspiration and prevent lung collapse during end-expiration at the low
transpulmonary pressures associated with normal breathing.