Definition of Air sac
1. Noun. A tiny sac for holding air in the lungs; formed by the terminal dilation of tiny air passageways.
Group relationships: Lung
Generic synonyms: Sac
Derivative terms: Alveolate
2. Noun. Any of the thin-walled extensions of the tracheae of insects.
3. Noun. Any of the membranous air-filled extensions of the lungs of birds.
Medical Definition of Air sac
Air Sac Pictures
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Lexicographical Neighbors of Air Sac
Literary usage of Air sac
Below you will find example usage of this term as found in modern and/or classical literature:
1. A Text-book of Zoology by Thomas Jeffery Parker, William Aitcheson Haswell (1921)
"The lungs with the aponeurosis or pleura p ib.l aperture of anterior thoracic air-sac; br. principal V 5' r , y 1 ? uP-h posterior end of the trachea, ..."
2. The Development of the Chick: An Introduction to Embryology by Frank Rattray Lillie (1908)
"just beneath the peritoneum. clavicular air-sac, o, Anterior thoracic _° 1, ... 4, Posterior thoracic air-sac, to expand into the abdominal 5, ..."
3. Respiration by John Scott Haldane (1922)
"Hence the extra proportion of CO2 extracted from the blood in the air-passage alveoli is practically taken from the air-sac alveoli, and this is why the ..."
4. The Scientific Memoirs of Thomas Henry Huxley by Thomas Henry Huxley, Michael Foster (1902)
"Hence the air-sac in front of the anterior intermediate in Apteryx must be the homologue ... air-sac does not extend beyond the front margin of the sternum, ..."
5. Comparative Anatomy of Vertebrates by Robert Wiedersheim (1907)
"The posterior thoracic air-sac presents the simplest and most constant relations, and never communicates with any of the neighbouring chambers, ..."