Across
- 2. breathes in oxygen and pumps out carbon dioxide
- 5. muscular middle part of the heart
- 7. upper chamber of the heart
- 10. pumps blood throughout the body
- 11. pumps blood back to the heart
- 12. between left ventricle and aorta
- 13. blood is pumped to wherever it has to go
Down
- 1. lower chamber of the heart
- 3. muscular wall that separates the heart
- 4. smaller veins
- 6. defends the circulatory system from unwanted substances
- 8. brief period of rest in the heart
- 9. carries blood wherever
- 11. blood travel throughout it