air sac

nouns

a tiny sac for holding air in the lungs; formed by the terminal dilation of tiny air passageways

air cell, air sac, alveolus

any of the thin-walled extensions of the tracheae of insects

air sac

is a part of

small air-breathing arthropod

is a type of (narrower)

a structure resembling a bag in an animal

any of the membranous air-filled extensions of the lungs of birds

air sac

is a part of

warm-blooded egg-laying vertebrates characterized by feathers and forelimbs modified as wings

is a type of (narrower)

a structure resembling a bag in an animal