1. It helps us breathe in oxygen and breathe out carbon dioxide.
2. Air enters the body through the nose.
3. The nose filters, warms, and moistens the air.
4. Air passes through the pharynx and larynx.
5. The larynx is also called the voice box.
6. Air travels down the trachea (windpipe).
7. The trachea divides into two bronchi.
8. Each bronchus enters one lung.
9. Inside the lungs, bronchi branch into bronchioles.
10. Bronchioles end in alveoli where gas exchange happens.
