How the Lungs Work
Explain how the respiratory system works in detail: air travels through the nose/mouth, down the trachea, into bronchi and bronchioles, reaching tiny air sacs (alveoli) in the lungs where oxygen passes into the blood and carbon dioxide passes out
What a learner can do afterwards
- Trace the air pathway: nose/mouth → trachea → bronchi → bronchioles → alveoli
- Explain gas exchange in the alveoli: oxygen passes into blood capillaries, carbon dioxide passes out
- Describe the mechanical process: the diaphragm contracts to help air enter the lungs, then relaxes as the lungs recoil and air flows out during quiet breathing
1 · Read
You know air comes in through your nose or mouth and moves down your windpipe to your lungs. Scientists call that windpipe the trachea. Inside your chest the trachea splits into two bronchi, the bronchi split into smaller bronchioles, and the bronchioles end at tiny air sacs called alveoli.
Zara breathes in through her nose. Air travels down her trachea, then through the bronchi and smaller bronchioles. It reaches alveoli, tiny air sacs wrapped in tiny blood vessels called capillaries. Oxygen passes into the blood, and carbon dioxide passes out into the air sacs.
A muscle called your diaphragm sits under your lungs. When it contracts it flattens and makes more room in your chest, so air is pulled all the way down to the alveoli. When it relaxes it domes back up, and the air is pushed out again.
Air travels from your nose or mouth, down through smaller and smaller tubes, until oxygen and carbon dioxide swap places in the alveoli.
Rewritten readings were written for this dataset.
2 · Watch
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Jobs that lean on this skill. Follow one to see everything it is built on.
8 questions wait behind this lesson, each with its answer explained. Every answer feeds the sky: stars light as they are learned, and dim when it is time to come back.