🐞 Insect breathing part 🐦 Bird breathing part

air sac

6.3

A thin part of an insect's breathing tubes that holds air and helps it breathe

noun
/ɛr sæk/

Specialized

: saco aéreo

Many flying insects rely on air sacs to efficiently deliver oxygen throughout their bodies.

Examples

The air sac helps insects breathe efficiently.
The structure of an air sac allows it to expand and contract with changing pressure.
Damage to the air sac system can impair an insect's ability to breathe.
Insects have multiple air sacs for respiration.
The structure of an air sac in insects allows it to expand and contract, facilitating efficient respiration.
Many flying insects use air sacs to enhance their oxygen circulation during flight.
Damage to the air sac can significantly affect an insect's ability to take in air.

Surface Forms

air sac singular

air sacs plural

Morphology

air + sac

The meaning 'a small sac containing air in the respiratory system' is directly and transparently derived from combining 'air' (the gas) with 'sac' (a pouch or cavity). This literal, compositional biomedical term follows standard noun+noun formation and is cross-linguistically common, so a B1 learner who knows both constituents will readily infer the meaning.

Etymology

Air sac is a name for a small sac of air inside an insect, like a tiny balloon attached to its breathing tubes. Because the bag holds and moves air through thin walls, the term explains why it means 'a thin-walled extension that helps with breathing'.