Across
- 2. River of life
- 4. The bridge between the brain and the rest of the body.
- 7. The basic structural unit of the nervous system.
- 9. The master organ of the human body.
Down
- 1. Tiny air sacs
- 3. Carry blood back to the heart
- 5. Major organ of the respiratory system
- 6. The pumping organ of the human body
- 8. Carry blood back to the heart