The heart receives oxygenated blood through the process of circulation. Veins carry deoxygenated blood to the right side of the heart, which pumps it to the lungs, where it becomes re-oxygenated and is then carried by the arteries to the left side of the heart for distribution to the body. Prolonged lack of oxygen to heart tissue due to blocked arteries can cause cell death.

3. Left side of the heart receives oxygenated blood from the lungs and pumps it to the body.

4. BOTH pumps work simultaneously. Both the atria contract together, followed by both ventricles pumping together. Source: Anatomy and Physiology, 6th edition, Scanlon & Sanders, pg 299