[The structure and ultrastructure of the lung in chickens]

Ultrastructural investigations were carried out on the lung of broiler birds. It was confirmed that the air-blood barrier located in the respiratory bronchioles consists of three layers as it does in the alveoles of mammals. Besides, it was found that similarly to the picture in mammals there are in chickens granular pneumocytes containing osmiophilic bodies that are in fact globularly winded parallel lamellae. These lamellar bodies were found to approach (in the course of their maturation) the surface of the large alveolar cells. Upon reaching their membrane the latter was lysed and the released surfactant spread over the cell surface.