[Scanning electron microscopy study of the lung].

The pulmonary parenchyma is characterized by a marked development of blood-tissue and gaz-tissue interfaces. Thus the study of the lung is easy by scanning electron microscopy. Numerous and various technics of sample preparation are described and discussed. They permit to carry out morphological and morphometrical studies of fine structures in the adult and foetal lung surface. The systematisation of the different parts of the pulmonary air tract (bronchi, bronchioli, alveolar ducts and alveoli) is analysed. The different epithelial cells are characterized by their apical differentiations and by their often specific localization. Bronchial (mucus), bronchiolar and alveolar (surfactant) secretions are studied after different fixations. The observation of the vascular network (arteries, veins and pulmonary capillaries) is performed after vascular injection of fixator liquid. The scanning electron microscope is also used to study the alveolar macrophage (in situ or in cell culture), the visceral surface of pleura, the pre and post-natal development of the lung parenchyma. The SEM is a complementary and modern method of lung observation. It gives a dynamic view of the fine structure of lung surfaces, which appears needful for the study of the local histophysiological processes.