[Ultrastructure of the pulmonary alveolus. Correlations with the endoalveolar tensioactive system].

The knowledge of chemical structure and physiologic role of endoalveolar tensioactive system are a progress of the last ten years. The authors deal with the origin, fate and relationships with pulmonary surfactant metabolism of alveolar cells. Morphology and functions of alveolar-capillary membrane, type I and II cells, bronchiolar non-ciliated Clara cells and alveolar macrophages have been outlined. Lamellar bodies, alveolar type II cells intracitoplasmatic inclusions were particularly considered, as well as tubular myeline structures.