air sac(redirected from alveolar sac)
Also found in: Thesaurus, Medical, Encyclopedia.
Related to alveolar sac: Alveolar ducts
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.
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
2. any of certain cavities in a bird's body connected with the lungs.
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.
Switch to new thesaurus
|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