Your heart has four chambers: two atria on top and two ventricles below.Blood low in oxygen flows into the right atrium from the body.It’s then pumped into the right ventricle and sent to the lungs to pick up oxygenNow, oxygen-rich blood returns to the left atrium.From there, it moves into the left ventricle, which pumps it out to the entire body.Valves in your heart ensure the blood flows in the right direction.When you exercise, your heart beats faster to supply your muscles with more oxygen.And that’s how your heart keeps you going strong, every single day!