Across
- 5. upper right chamber
- 7. oxyen-rich blood from lungs
- 8. blood to upper body
- 11. upper left chamber
- 12. left lower chamber
Down
- 1. biggest artery
- 2. oxygen poor blood to atrium
- 3. prevents blood back-flow between ventricle and atrium
- 4. prevents back-flow of blood from ventricle
- 6. prevents back-flow from artery
- 8. muscle wall between heart
- 9. oxygen-poor blood to lungs
- 10. lower right chamber