alveolar

Alveolar is an adjective used in anatomy, dentistry, and linguistics to refer to structures associated with an alveolus or with the alveolar ridge. The term derives from Latin alveolus meaning small cavity or air sac.

In anatomy, the alveolar sacs are the terminal units of the lungs where most gas exchange occurs. They consist of tiny air sacs called alveoli, enveloped by a dense network of capillaries. Type I pneumocytes form the thin gas-exchange barrier, while Type II pneumocytes secrete surfactant to reduce surface tension. The alveolar membrane's integrity is essential for efficient oxygen uptake and carbon dioxide removal. Various conditions, such as pneumonia, edema, fibrosis, or emphysema, can alter alveolar function or structure.

In dental anatomy, the alveolar process or alveolar bone supports the teeth within the maxilla and mandible. Each socket is called an alveolus. The alveolar ridge forms the bony crest that bears the teeth; after tooth loss, the alveolar bone may resorb and affect prosthodontic treatment. The alveolar mucosa lines the region and the periodontal ligaments secure teeth to the bone.

In phonetics, alveolar describes sounds produced with the tongue contacting the alveolar ridge behind the upper front teeth, such as t, d, s, z, n, and l in many languages. Alveolar sounds contrast with dental articulations, where the tongue touches the teeth, and with postalveolar articulations, produced a little further back.