Across
- 3. Chamber at the bottom
- 4. Name of the system
- 6. What carries blood away from the heart
- 8. What the walls of the heart are made from
- 9. Number of chambers in the heart
Down
- 1. A shortening or tensing of the muscle
- 2. Chamber at the top
- 5. What returns blood to the heart
- 7. Organ that pumps blood