How the Human Heart Works?

Human heart has four chambers i.e 2 atri and 2 ventricles. The right atrium and the right ventricle receive impure blood from the body and send it to lungs for purification. The left atrium and left ventricle receives pure blood from the lungs and pump it into aorta the major blood vessel of the human body. Branches of aorta then distribute this pure blood all over the body.