Across
- 1. Vessels with thick muscular walls and small lumen
- 3. The upper chambers of the heart
- 6. Tiny blood vessels where gas exchange occurs
- 7. Blood vessel carrying blood away from the heart
- 9. Red protein in blood that carries oxygen
- 10. Heart chamber that pumps blood to the body
- 11. Blood vessel carrying blood towards the heart
- 12. Vessels with valves to prevent backflow
Down
- 2. Heart chamber that pumps blood to the lungs
- 4. The circulation between heart and lungs
- 5. The largest vein in the body
- 7. Main artery leaving the left ventricle
- 8. Resting heart rate is often measured in this unit