Alveolus (; pl. alveoli, adj. alveolar) is a general anatomical term for a concave cavity or pit. Uses in anatomy and zoology Pulmonary alveolus, an air sac in the lungs Alveolar cell or pneumocyte Alveolar duct Alveolar macrophage Mammary alveolus, a milk sac in the mammary glands Alveolar gland Dental alveolus, also known as "tooth socket", a socket in the jaw that holds the roots of teeth Alveolar ridge, the jaw structure that contains the dental alveoli Alveolar canals Alveolar process Arteries: Superior alveolar artery (disambiguation) Anterior superior alveolar arteries Posterior superior alveolar artery Inferior alveolar artery Nerves: Anterior superior alveolar nerve Middle superior alveolar nerve Inferior alveolar nerve Uses in botany, microbiology and related disciplines Surface cavities or pits, such as on the stem of Myrmecodia species Pits on honeycombed surfaces such as receptacles of many angiosperms Pits on the fruiting bodies of fungi such as Boletus or the ascocarps of fungi such as typical ascomycetes Pits on the valves of the tests of many diatoms Membrane supporting vesicles of the alveolates Uses in linguistics Alveolar consonant, a linguistic vocalization depending upon touching tongue to alveolar ridge Alveolar stop See also Alveolar soft part sarcoma, a very rare type of soft-tissue sarcoma, Acinus, considered by some (but not all) sources to be synonymous with Alveolus Human anatomy Animal anatomy