Across
- 2. connects bone to bone.
- 5. fights bacteria.
- 6. main organ in nervous system.
- 8. it is at the end of a bone.
Down
- 1. nerve cells travel up it to the brain.
- 2. in the respiratory system.
- 3. protects your lungs and heart.
- 4. takes oxygen around the body.
- 7. pumps blood around the body.
- 8. protects the brain.
- 9. connects muscle to bones.