1. The Respiratory system By Erika

2. Respiratory System includes the nose, mouth, windpipe and the lungs. Your respiratory systems purpose is to oxygenate your blood.

3. The purpose of the respiratory system is to supply the blood with oxygen so that the blood can deliver oxygen to all the parts of the body. The respiratory system does this through breathing. When we breathe in we inhale oxygen and exhale carbon dioxide. This is the change of the gases.

4. Oxygen enters the respiratory system through the mouth and the nose. The oxygen then passes through the larynx and the trachea. The trachea then goes to the chest cavity where the trachea then splits into two tubes called the bronchi. Each bronchus then divides to form bronchial tubes. The bronchial tubes lead into the lungs where they divide into many smaller tubes which connect to tiny sacs called alveoli. Then the blood from our veins releases carbon dioxide into the alveoli. The carbon dioxide goes out the same tube as the lungs when you exhale.