air sac

American  

noun

1. a sac containing air.

2. alveolus.

3. any of certain cavities in a bird's body connected with the lungs.

4. a saclike dilation of the wall of a trachea in many insects.

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air sac British  

noun

1. any of the membranous air-filled extensions of the lungs of birds, which increase the efficiency of gaseous exchange in the lungs

2. any of the thin-walled extensions of the tracheae of insects having a similar function

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air sac Scientific  

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 enlargement in the trachea of an insect.

4. A baglike 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.

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Etymology

Origin of air sac

First recorded in 1820–30

Example Sentences

See Examples For:

air sac

A micro CT scan - that produces 3D images - revealed the contents of the egg, complete with the air sac.

From BBC ● Feb. 11, 2024

They have a dedicated tymbal organ, and an abdominal air sac likely serves to amplify the sound.

From Scientific American ● Jun. 14, 2021

“Every breath we take has to be expertly conveyed from the tip of the nose to the last air sac in the lungs,” Merati said.

From Seattle Times ● Apr. 6, 2021

From the posterior air sac, air enters the lungs, and the anterior air sac in front of the lungs.

From Textbooks ● Jan. 1, 2015

Physalia; a b air sac with crest c, m bunches of individuals, n central tentacles, t t expanded tentacles.

From Seaside Studies in Natural History Marine Animals of Massachusetts Bay. Radiates. by Agassiz, Alexander