Across
- 3. the name for the hard, outer layer of bone
- 12. basic unit of the nervous system
- 13. small blood vessels
- 14. a messenger system that uses hormones to carry out specific functions
- 15. connects the kidney to the bladder
- 16. the system that protects body and stores calcium
- 18. steady internal conditions when external conditions change
- 20. part of the digestive and endocrine systems
- 21. connects the pharynx to the bronchi
Down
- 1. the parts of food used by the body to grow and survive
- 2. signal molecule released by organs of the endocrine system
- 4. these carry blood away from the heart
- 5. a measure of the amount of energy in food
- 6. the system that breaks down food
- 7. produces urea by breaking down proteins
- 8. part of the central nervous system
- 9. the system that removes waste
- 10. system that coordinates actions and sensory information
- 11. this describes the inner layer of bone
- 17. the type of muscle in the heart
- 19. the type of muscle in the stomach and bladder