Across
- 4. prevents blood from going backwards in the system
- 5. carries no air blood
- 6. muscle thick layer of the heart
- 8. carries air blood
- 9. receives blood from the circulatory system
Down
- 1. small blood vessels that connect the arteries and veins to the heart
- 2. makes the beat and tells the heart when to pump
- 3. pumps blood to the rest of the body
- 4. cava largest vein that carries blood away from the heart
- 7. separates the two sides of the heart
- 8. also carries air blood