1. The respiratory system

5. Oral Cavity- Oxygen can also enter through your mouth but is not filtered.

6. Epiglottis- It allows air to pass through the larynx and into the rest of the respiratory system. When swallowing food or drink, it covers the entrance to the larynx to prevent food and drink from entering the windpipe.

7. Pharynx- It provide a passageway for the respiratory and digestive tracts. It allows common passageway for air into your lungs and food into your stomach. The upper part of the pharynx will only allow food to pass through, and the lower part of the pharynx allows air, fluids, and food to pass through.

9. Trachea- A principal tube that carries air to and from the lungs.

10. Lung- Occupying the chest cavity together with the heart and functioning to remove carbon dioxide from the blood and provide it with oxygen.

11. Aorta- The largest artery in the body, originating from the left ventricle of the heart and extending down to the abdomen, where it branches off into two smaller arteries . The aorta distributes oxygenated blood to all parts of the body through the systemic circulation.

12. Pulmonary Artery- Carry deoxygenated blood from the heart to the lungs.

14. Alveolar Sac- Where the chemical change takes place and where blood cells pick up oxygen and drop off carbon dioxide.

15. Sinus- A cavity in the bones of your skull that helps moisten and heat the air that you breath.

16. Capillaries-Tiny blood vessels that pass blood from the arteries into the veins. Capillaries supplying blood to an organ, when taken in whole.

17. Bronchiole- Keep splitting up until they reach your alveoli.