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 pull air in and relaxes to push air out
The lesson
You already know your diaphragm pulls air in and pushes it out. But where does that air actually go? Follow one breath as it travels deep inside your chest.
Zara breathes in through her nose. The air rushes down her trachea like a hallway, then splits into her bronchi, like two branching tunnels. The tunnels keep splitting into smaller and smaller bronchioles until the air reaches the alveoli, tiny air sacs wrapped in blood vessels. There, oxygen slips into her blood, and carbon dioxide slips out.
Remember: your diaphragm contracts to pull air in and relaxes to push air out. That squeeze and release is what drives air all the way down to the alveoli.
Air travels from your nose or mouth, down through smaller and smaller tubes, until oxygen and carbon dioxide swap places in the alveoli.
Watch it
Where it sits
Learn first
This opens up
Where this leads
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.