Across
- 2. muscle that pumps blood
- 4. the large bone in the upper leg
- 5. blood cells that carry oxygen
- 6. the system that includes bones and joints
- 8. main organ of the respiratory system
- 10. the protective cage around the lungs an heart
- 12. the protein in red blood cells that carries oxygen
- 13. the fluid part of lungs
- 14. strong tissue connecting bone to bone
- 15. system that supports and protects the body
Down
- 1. system that transports blood throughout the body
- 3. the tube that carries air from the throat to the lungs
- 7. tiny air sacks in the lungs where gas exchanged happens
- 9. the breathing muscle located below the lungs
- 11. the tiny blood vessels where exchange of gases and nutrients occurs