Air’s Path Through the Body

When you breathe in, air enters through your nose or mouth and travels down a tube in your neck. It then splits into two branches and reaches the lungs, where tiny sacs pass oxygen into your blood.

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In the picture

Nose — air enters here and is warmed and moistened.
Windpipe — the ridged tube that carries air down the neck.
Bronchi — the point where the windpipe splits into two branches, one for each lung.
Alveoli — tiny sacs at the end of the branch where oxygen passes into the blood.

Examples

Breathing in the steam of a hot bowl of soup through your nose.
Blowing out a candle with lips pursed.

Key takeaways

Air follows one continuous route: nose or mouth, windpipe, bronchi, lungs.
Oxygen crosses into the blood in the tiny alveoli sacs, and carbon dioxide comes back out.