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