1. De-oxygenated blood enter Rt. Atrium from Superior and Inferior Vena Cavae ¯
- 2. From Rt. Atrium blood flows through Rt. Atrioventricular (AV) Valve to Rt. Ventricle ¯
- 3. Rt. ventricle contraction forces blood through the Pulmonary Semi-lunar Valve into Pulmonary trunk ¯
4. Blood in Pulmonary trunk flow to Rt. and Lt. Pulmonary arteries ¯
5. Rt. and Lt. Pulmonary arteries branching from pulmonary trunk carry de-oxygenated blood (blood rich in CO2) to the Rt. and Lt. Lungs ¯
**BLOOD IS NOW OXYGENATED**
6. Oxygenated blood leaves lung via Rt. and Lt. Pulmonary Veins ¯
7. Rt. and Lt. Pulmonary Veins empty into Lt. Atrium ¯
8. Lt. Atrium blood flow INTO the Bicuspid (Lt. AV) Valve into Lt. Ventricle ¯
9. Lt. Ventricle contraction forces blood via the Aortic Semi-lunar Valve to Ascending Aorta. ¯
10. At base of Ascending Aorta O2 rich blood flows via Rt. and Lt. Coronary Arteries to the Heart ¯
11. Blood in Ascending Aorta goes to Ascending Arch for Systemic Circulation