title: Cellular components of the alveolar unit.
mesh_terms: D000818:Animals; D002196:Capillaries / Q000648:ultrastructure; D004727:Endothelium / Q000502:physiology; D004848:Epithelium / Q000648:ultrastructure; D006801:Humans; D008168:Lung / Q000166:cytology; D008264:Macrophages / Q000648:ultrastructure; D008854:Microscopy, Electron; D010100:Oxygen / Q000097:blood; D011650:Pulmonary Alveoli / Q000098:blood supply / Q000166:cytology* / Q000502:physiology
chemical_list: D010100:Oxygen