Across
- 3. The gas that our cells need to produce energy from food
- 4. The soft tissue inside bones where new blood cells are made
- 6. A flexible tissue that cushions the spaces between bones at a joint
- 8. Blood vessels that use valves to carry blood back to the heart
- 9. The process of breathing air into the lungs
- 11. Tiny, thin walled blood vessels where nutrients and gases are exchanged with cells
- 14. Tough bands of tissue that connect one bone to another bone
- 15. The main windpipe that connects the throat to the bronchi
Down
- 1. The organ that pumps blood continuously around the body
- 2. The place where two bones meet, which allows our skeleton to move
- 5. The type of vessel that carries blood away from the body
- 7. The tiny air sacs at the end of the bronchioles where oxygen enters the blood
- 10. The gas that is a waste product of cellular respiration and is exhaled
- 12. The primary organs of the respiratory system where gas exchange happens
- 13. The sheet of muscle under the lungs that flattens to pull air in