Pulmonary alveolar macrophages in calf: an electron microscopic study

Alveolar phagocytes were found as free cells in the alveolar spaces of calf's lung. These cells appeared large with spherical or irregular nucleus. Their cell surface was rough due to the presence of many cytoplasmic extension and pseudopodia. In cytoplasmic structure, the cells were somewhat similar to the other macrophages. Their cytoplasm showed a variety of inclusions and a large number of phagolysosomes. The alveolar macrophages are suggested to be responsible for the removal of the small foreign particles and the degraded surfactant from the lumen of the air-alveoli