air sac

noun

a sac containing air.
alveolus (def. 2).

any of certain cavities in a bird's body connected with the lungs.
a saclike dilation of the wall of a trachea in many insects.

Origin of air sac

First recorded in 1820–30

Words Nearby air sac

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

How to use air sac in a sentence

During intense exercise, the heart can become overworked, which may lead to some fluid buildup in the small air sacs of the lungs, known as pulmonary edema, a condition commonly connected to heart problems.
Do you sometimes taste blood when working out? Here’s what might be happening. | Allyson Chiu | October 8, 2021 | Washington Post
The virus invades the lining of the lungs, including the alveoli, tiny air sacs that capture oxygen from each breath and quickly pass it into the bloodstream.
We Didn’t Evolve for This - Issue 94: Evolving | Claudia Geib | January 6, 2021 | Nautilus
Pneumonia occurs when “air sacs in the lungs fill with fluid, limiting their ability to take in oxygen and causing shortness of breath, cough and other symptoms,” Galiatsatos writes.
The covid-19 symptoms to watch out for | Angela Fritz | December 2, 2020 | Washington Post
ARDS occurs when air sacs become filled with fluid leaking from the tiny blood vessels in the lungs, causing the lungs to fail.
These COVID symptoms could last for months | Sara Kiley Watson | September 22, 2020 | Popular-Science
But the joints of the backbone in front of the sacrum receive their air from the cervical air sac.
Dragons of the Air | H. G. Seeley

These animals are said to possess an air-sac in the throat, at the back of the trachea (or windpipe), as in Ateles.
A Hand-book to the Primates, Volume 1 (of 2) | Henry O. Forbes
The cheek-bones enormously swollen along the side of the nose; in the neck a large air-sac.
A Hand-book to the Primates, Volume 1 (of 2) | Henry O. Forbes

British Dictionary definitions for air sac

air sac

noun

any of the membranous air-filled extensions of the lungs of birds, which increase the efficiency of gaseous exchange in the lungs
any of the thin-walled extensions of the tracheae of insects having a similar function

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Scientific definitions for air sac

air sac

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.

A saclike enlargement in the trachea of an insect.
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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