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In the alveoli, oxygen from the air is absorbed into the blood. Carbon dioxide, a waste product of metabolism, travels from the blood to the alveoli, where it can be exhaled. Between the alveoli is a thin layer of cells called the interstitium, which contains blood vessels and cells that help support the alveoli.
HISTOPATHOLOGY OF ALVEOLI ALVEOLAR WALL 1. Alveolar epithelial cells-Type I pneumocytesType II pneumocytes 2. Basement Membrane 3. Interstitial Space-CollagenElastinUnmyelinated NervesMacrophages 4. Capillary Basement Membrane 5. Capillary Endothelial Cells..