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Related to air sac: bronchiole
1. An air-filled space in the body of a bird that forms a connection between the lungs and bone cavities and aids in breathing and temperature regulation.
2. See alveolus.
3. A saclike, thin-walled enlargement in the trachea of an insect.
4. An inflatable pouch attached to the larynx in certain mammals, including the nonhuman great apes.
American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
1. (Zoology) any of the membranous air-filled extensions of the lungs of birds, which increase the efficiency of gaseous exchange in the lungs
2. (Zoology) any of the thin-walled extensions of the tracheae of insects having a similar function
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014
2. any of certain cavities in a bird's body connected with the lungs.
Random House Kernerman Webster's College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.
1. An air-filled space in the body of a bird that forms a connection between the lungs and bone cavities. See alveolus.
2. A sac-like enlargement in the trachea of an insect.
3. A bag-like piece of skin or tissue below the jaw of certain animals, such as the bullfrog and orangutan, that can be inflated to increase sound production.
The American Heritage® Student Science Dictionary, Second Edition. Copyright © 2014 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
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|Noun||1.||air sac - a tiny sac for holding air in the lungs; formed by the terminal dilation of tiny air passageways|
lung - either of two saclike respiratory organs in the chest of vertebrates; serves to remove carbon dioxide and provide oxygen to the blood
|2.||air sac - any of the thin-walled extensions of the tracheae of insects|
insect - small air-breathing arthropod
|3.||air sac - any of the membranous air-filled extensions of the lungs of birds|
bird - warm-blooded egg-laying vertebrates characterized by feathers and forelimbs modified as wings
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