The lungs and respiratory system allow us to breathe. They bring oxygen into our bodies (called inspiration, or inhalation) and send carbon dioxide out (called expiration, or exhalation).

This exchange of oxygen and carbon dioxide is called respiration.

Lungs and Respiratory System (for Teens) | Nemours KidsHealth

https://kidshealth.org/en/teens/lungs.html

Each day you breathe about 20,000 times. Find out more about the lungs and breathing process.