Understanding Blood Flow: Which Side of the Heart Carries Oxygenated Blood?

The left side of the heart contains oxygenated blood. The right side of the heart pumps deoxygenated blood to the lungs, where it picks up oxygen and becomes oxygenated. The oxygenated blood then returns to the heart and enters the left atrium. From the left atrium, the oxygenated blood flows into the left ventricle, which pumps it out to the body.