The cardiovascular system

123456789101112
Across
  1. 1. Vessels with thick muscular walls and small lumen
  2. 3. The upper chambers of the heart
  3. 6. Tiny blood vessels where gas exchange occurs
  4. 7. Blood vessel carrying blood away from the heart
  5. 9. Red protein in blood that carries oxygen
  6. 10. Heart chamber that pumps blood to the body
  7. 11. Blood vessel carrying blood towards the heart
  8. 12. Vessels with valves to prevent backflow
Down
  1. 2. Heart chamber that pumps blood to the lungs
  2. 4. The circulation between heart and lungs
  3. 5. The largest vein in the body
  4. 7. Main artery leaving the left ventricle
  5. 8. Resting heart rate is often measured in this unit