Abstract

Pulmonary surfactant consists of about phospholipids, amphipathic molecules characterized by having a polar head which is hydrophilic, whereas the fatty acids, at the other end of the molecule, are decidedly hydrophobic. Because the molecule is partly explicitly hydrophobic it cannot be completely surrounded by water molecules, the fatty acids must stay away from the water and they will if they adjoin the fatty acids of other phospholipid molecules. This is probably the reason that the molecules, as they are synthesized, form typical arrangements in the moist cytoplasm. They are known as lamellar bodies and consist of concentric bilayer shells, layered one outside the other.

Keywords: Bilayer shells; Air-liquid interface; Plasma proteins; Alveolar expansion; Amphipathic molecule; Pre-mature infants;