Across
- 3. produces heat
- 6. maintains acid-base balance
- 9. synthesizes vitamin D
- 12. the control center of the nervous system
- 13. pathway air takes between the mouth and the lungs
- 14. eliminates indigestible material
- 15. site of blood cell formation
Down
- 1. provides a protective case for the brain
- 2. responds to internal and external change
- 4. production of offspring
- 5. transports materials in body via blood pumped by heart
- 7. keeps blood supplied with oxygen
- 8. returns fluids to blood vessels
- 10. secretes regulatory hormones
- 11. organ that filters blood in the urinary system