The alveolar septum is the thin wall which separates one |alveolus| from another in the large alveolar cluster, or sac. The alveolar septum may be fully formed or only partially formed, as |alveoli| may be completely spherical or partially joined with a neighboring |alveolus|. Within the material of the alveolar walls and septa are the |capillary networks| which bring the oxygen-poor, carbon dioxide-rich ~blood~ to be regenerated.
