Breathing exchanges gases with the outside air and the aveoli of the lungs. The diaphragm and inner muscles help with the expansion of the lungs.

More About the Respiratory System

•The respiratory tract cleans, warms and moisten the air during its trip to the lungs. •When you breathe in your diaphragm contracts and flattens out.

•Your lungs are pink and squishy

•A sac called the pleura surrounds the lungs and protects them

•A healthy adult breathes in and out 12 times every minute

How the System Works

First, you breathe in air. It then gets cleaned by the tiny hairs on your nose called the cilla. The air then leaves the nasal cavity and enters the throat, where it passes the voices box. All the mucus is exited by coughing and then enters each lung.