肺表面活性物质 ( Pulmonary surfactant,PS)是由 型肺泡细胞和呼吸性细支气管壁上的 Clara细胞合成和分泌的脂质和蛋白质的混合物 ,其主要生理作用是降低肺泡液 -气表面张力 ,减少吸气阻力 ;减少肺泡液的生成 ,防止肺水肿的发生 ;调节表面张力 ,稳定肺泡内压。近年来发现肺表 Pulmonary surfactant (PS) is a mixture of lipids and proteins synthesized and secreted by the type II pneumocytes and Clara cells on the respiratory bronchiole wall. Its main physiological function is to reduce alveolar fluid-air surface tension and reduce Inspiratory resistance; reduce the formation of alveolar fluid to prevent the occurrence of pulmonary edema; regulate the surface tension and stabilize the pressure inside the alveoli. In recent years, the lungs were found