The left side of your heart receives oxygen-rich blood from your lungs and pumps it through your arteries to the rest of your body. Your heart has four separate chambers that pump blood, two on the right side and two on the left. How does blood flow through the heart? Blood flows through your heart and lungs in four steps: The right atrium receives oxygen-poor blood from the body and pumps it to the right ventricle through the tricuspid valve.
