Across
- 2. carries oxygen
- 4. filters the blood for waste.
- 7. where digestion begins
- 8. fights off disease
- 9. the basic unit of structure
- 11. smallest blood vessel
- 13. organs that work together
- 15. liquid part of blood
Down
- 1. important part in making scabs
- 3. where most water is absorbed
- 5. lower part of the heart
- 6. tiny sacs of lung tissue
- 10. muscular tube connected to the mouth and stomach
- 12. a muscular sac
- 14. where most digestion starts