Across
- 3. windpipe
- 5. muscle that separates the thoracic cavity from the abdominal cavity
- 7. passageway for both air and food
- 8. one of two branches leading into each lung
- 9. occurs when the diaphragm contracts
- 12. voice box
- 14. vein bringing blood back from the lungs to the heart
- 15. largest artery of the body
- 17. wall dividing the left and right sides of the heart
- 19. tiny air sacs in the lungs
- 22. found inside the larynx
- 23. pumps blood
- 24. substance in blood whose level regulates breathing
- 26. bottom chamber of a heart
- 27. artery taking blood to the lungs from the heart
Down
- 1. flap that blocks the airway when swallowing
- 2. protective sac enclosing the heart
- 4. large vein entering the heart from the upper body
- 6. part of the brain which controls breathing
- 10. further divisions of tubes branching off the bronchi
- 11. oxygen-carrying molecule in the blood
- 13. fluid portion of blood
- 14. tiny pieces of cells that help blood clot
- 15. top chamber of a heart
- 16. side of the heart dealing with deoxygenated blood
- 18. small blood vessel where gas exchange takes place
- 20. large vein entering the heart from the lower body
- 21. white blood cells
- 25. red blood cells