Across
- 2. the trachea branches into two narrower tubes called _______ that lead into the lungs
- 5. the movement of air into and out of the lungs
- 9. every cell in the body needs oxygen for a chemical reaction called
- 10. the main organs of the respiratory system
Down
- 1. below the lungs is a large muscle called the ________ that contracts as you breathe
- 3. signals from the ________ system trigger breathing
- 4. air moves into a windpipe or _______, a tube that is held open by C-shaped rings of cartilage
- 6. the nervous, circulatory and respiratory systems work together to maintain ________
- 7. a tube-like passage way at the top of the throat that receives air, food, and liquid from the mouth or nose
- 8. the tubes in the lungs end in microscopic sacs called ________