3. Function: Distributes oxygen and nutrients throughout the body

4. Click picture to play

5. Function: Pump blood throughout body Two Main Pathways: 1) Pulmonary circulation –Between heart & lungs –Oxygen-poor blood 2) Systemic Circulation –Between heart & body –Oxygen-rich blood Click picture to play

6. 4 Chambers Blood flows from atrium to ventricles Valves ensure one way flow Septum

7. 1) Deoxygenated (used) blood enters right atrium

8. 2) Blood pumped from right atrium into right ventricle Valve prevents backwards flow

9. 3) From the right ventricle, blood travels through the pulmonary arteries towards the lungs

10. Deoxygenated (used) blood enters lungs Gases exchanged with alveoli Oxygenated (new) blood returns to heart

11. 4) From the lungs, oxygenated blood enters the left atrium through the pulmonary veins

12. 5) Blood pumped into left ventricle Valve prevents backwards flow

13. 6) Left ventricle pumps blood to aorta Aorta directs oxygenated blood throughout the body

15. Quick Review Deoxygenated blood is pumped towards the lungs Lungs remove CO 2 and add O 2 Oxygenated blood returns to heart