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air sac

air sac
1. Any one of a series of thin-walled sacs in birds that are connected to the lungs and increase the efficiency of ventilation. Some of the air sacs penetrate the internal cavities of bones.

2. A structural extension to the trachea in insects, which increases the surface area available for the exchange of oxygen and carbon dioxide in respiration.

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"air sac." A Dictionary of Biology. . Encyclopedia.com. 22 Aug. 2017 <http://www.encyclopedia.com>.

"air sac." A Dictionary of Biology. . Encyclopedia.com. (August 22, 2017). http://www.encyclopedia.com/science/dictionaries-thesauruses-pictures-and-press-releases/air-sac-0

"air sac." A Dictionary of Biology. . Retrieved August 22, 2017 from Encyclopedia.com: http://www.encyclopedia.com/science/dictionaries-thesauruses-pictures-and-press-releases/air-sac-0

air sac

air sac In birds, a thin-walled extension of the lung which penetrates into the body cavity, entering the bones and forming air spaces. The lightweight bones that result are particularly important to birds. Anhimidae (screamers) have air spaces that penetrate to the tibia.

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
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"air sac." A Dictionary of Zoology. . Encyclopedia.com. 22 Aug. 2017 <http://www.encyclopedia.com>.

"air sac." A Dictionary of Zoology. . Encyclopedia.com. (August 22, 2017). http://www.encyclopedia.com/science/dictionaries-thesauruses-pictures-and-press-releases/air-sac

"air sac." A Dictionary of Zoology. . Retrieved August 22, 2017 from Encyclopedia.com: http://www.encyclopedia.com/science/dictionaries-thesauruses-pictures-and-press-releases/air-sac