Definition of alveolus in English:


Syllabification: al·ve·o·lus
Pronunciation: /alˈvēələs

noun (plural alveoli /-ˌlī/)

chiefly Anatomy
  • 1A small cavity, pit, or hollow, in particular.
    More example sentences
    • Recent studies have shown that it may have a critical role in lung growth, affecting new formation of both alveoli and pulmonary blood vessels.
    • The main wall of the duct between alveoli contains smooth muscle.
    • We did not find differences in the content of elastic fibers in the distal alveoli between patients with asthma and control subjects.
  • 1.1Any of the many tiny air sacs in the lungs where the exchange of oxygen and carbon dioxide takes place.
    More example sentences
    • Scientists also suspect that air pollutants might dampen the growth of alveoli, tiny air sacs in the lungs.
    • Holes in the lungs occur as the alveoli air sacs break down.
    • As altitude increases above sea level, atmospheric pressure drops with a parallel decrease in the amount of oxygen available at the blood/air interface in the lung alveolus.
  • 1.2The bony socket for the root of a tooth.
    More example sentences
    • No preserved teeth or alveoli can be observed in the premaxilla and dentary bones.
    • The tooth row is present throughout the entire preserved length of the jaw and possesses 16 teeth and empty alveoli.
    • Only a few, fragmentary teeth are preserved, and judging by the fragments and the size of alveoli, the teeth were gracile.
  • 1.3An acinus in a gland.
    More example sentences
    • Carbon dioxide in the lungs is 4.5 to 6%, in the blood of alveolus 6.5% and in cells 7%.



Pronunciation: /-lit, -ˌlāt/
More example sentences
  • The Siddall group addressed the molecular phylogeny of three, very similar, alveolate genera.
  • Several workers have suggested that the entire alveolate clade is derived from a photosynthetic ancestor.
  • One of them corresponded to an alveolate sequence belonging to the recently described marine.


late 17th century: from Latin, 'small cavity', diminutive of alveus.

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