Respiratory system

2. – The throat; connects the mouth and nose to the esophagus and trachea.
3. The organs where oxygen is absorbed into the blood and carbon dioxide is removed.
4. – The two large tubes that branch off from the trachea into each lung.
6. – Small blood vessels surrounding the alveoli, where gas exchange occurs.
9. – The process of inhaling oxygen and exhaling carbon dioxide.
11. – A large muscle at the base of the lungs that helps with breathing.
13. – The part of the body where air enters the respiratory system.

1. – A small flap that prevents food from entering the windpipe when swallowing.
5. – The gas that the body needs to breathe in for energy.
6. – Tiny hair-like structures that line the airways and help filter out dust and other particles from the air.
7. – Tiny air sacs in the lungs where gas exchange takes place.
8. – The windpipe; carries air to and from the lungs.
10. Dioxide – The waste gas that the body exhales.
12. – A sticky substance produced by the nose to trap dust and microbes.