list in order the events of blood flow through the heart, starting from the blood entering the atria from the vena cava. 1. Blood enters the right atrium from vena cava
2. Blood flows to right ventricle
3. Right ventricle contracts forcing blood into pulmonary vessels
4. Blood returns from lungs to left atrium via pulmonary veins
5. Blood flows to the left ventricle
6. Oxygenated blood leaves left ventricle via ascending aorta