1. Is there a pressure difference? Is there an open valve? Where will blood flow? *atrium →ventricle *ventricle →atrium *ventricle →aorta *aorta →ventricle

2. Where will blood flow?

3. Where will blood flow? From atrium to ventricle!

4. Is there a pressure difference? Is there an open valve? Where will blood flow? *atrium →ventricle *ventricle →atrium *ventricle →aorta *aorta →ventricle

5. Where will blood flow?

6. Where will blood flow? From ventricle to aorta!

7. Is there a pressure difference? Is there an open valve? Where will blood flow? *atrium →ventricle *ventricle →atrium *ventricle →aorta *aorta →ventricle

8. Where will blood flow?

9. Where will blood flow? Absolutely nowhere!

10. Now let’s look at a figure from the textbook that shows the actual pressure changes in the atrium, ventricle and aorta.

11. Fig. 20-17. Variations in aortic, atrial and ventricular pressures throughout one cardiac cycle.

15. Fig. 20-17