Across
- 1. this cage-like structure moves in the chest when breathing
- 4. alternative entry point for inhalation
- 5. oxygen burns this to release energy
- 8. what are the alveoli covered with
- 9. first part of airway where inhaled air passes
- 10. entry point of air into body
- 11. the organ system that involves breathing
- 18. substance in red blood cells which carries oxygen
- 19. the purpose of respiration is to release this
Down
- 2. divides into two, one branch to each lung
- 3. a tissue type where respiration occurs continually
- 6. a product of respiration
- 7. the watery part of blood that carries carbon dioxide
- 8. the waste product of respiration
- 12. small air sac in the lungs
- 13. needs to get into bloodstream to be carried to cells.
- 14. the process that moves gases in and out of the blood
- 15. sheet of muscle that contracts to expand chest cavity
- 16. a breath out
- 17. a breath in