[TA] (1) the tissue intervening between two adjacent pulmonary alveoli; it consists of a close-meshed capillary network covered on both surfaces by thin alveolar epithelial cells; (2) one of the bony partitions between the tooth sockets of the mandible and maxilla (septa interalveolaria mandibulae et maxillae). SYN: septum interalveolare [TA], alveolar septum, septal bone.