Across
- 4. tube that splits air into the lungs
- 5. tiny sacs on the lungs where oxygen enters blood
- 8. blood cells fight infections in body
- 10. system a bunch of organs that work together to complete major functions
- 11. Specialized cells that complete the same tasks
- 13. structure composed by tissue
- 14. a change in the environment that the body responds to
Down
- 1. tube for air
- 2. muscle that enables breathing
- 3. blood cells carry oxygen
- 6. bring oxygen into the body and carbon dioxide out
- 7. pieces of old cells that clot when bleeding
- 9. action completed in response to the stimulus
- 12. material that holds the other parts together