The Systems of the Body

The Systems of the Body

Respiratory System

The respiratory system takes the air , and then takes oxygen from the air . Our cells use this oxygen . As our cells work , they make carbon dioxide gas . The waste gas leaves our body when we breathe out . Our nose gets air ready for our lungs . Blood in the blood vessels warms the air we breathe in . Sometimes the air we breathe is very dry . Our nose also adds moisture to the air . Our nose also helps clean the air we breathe Tiny hairs inside our

nose trap dust and dirt in the air . Our nose makes sticky liquid called mucus that also traps dust and dirt and keeps them from going into our lungs . When we blow our nose , we get rid of anything trapped in the mucus

Our nose warms , moistens , and cleans the air we breathe in . Then the air goes on to the rest of our respiratory system . On one hand , when we inhale , or breathe in , air goes into our trachea , a hollow tube in our chest . Our trachea divides into two bronchial tubes . These tubes take the air into our lungs . Inside our lungs , our bronchial tubes divide into smaller and smaller tubes . The smallest tubes are thinner than a hair and lead to tiny air sacs

Each of our lungs is made of millions of tiny air sacs . These air sacs look like bunches of tiny balloons . The wall of each air sac is very thin and...