1. where chemicals pass between cells and blood platelets 2. an atmospheric gas expelled by body cells ventricle 3. a vessel that carries blood away from the heart cells 4. the liquid that carries chemicals and blood cells through the circulation alveoli 5. air sacs within the lungs plasma 6. a lower part of the heart blood vessels 7. any of the arteries, veins or capillaries that carry blood through the body serum 8. vessels that carry blood back to the heart atrium 9. an upper part of the heart trachea 10. need food and oxygen to live artery 11. the thin-walled tube which carries air from the nose and mouth into the lungs red blood cells 12. the liquid part of blood left over after clotting has taken place carbon dioxide 13. to stop bleeding veins 14. carry oxygen to the cells and take carbon dioxide away capillaries 15. the body fight infection white blood cells