Why is the left ventricle wall more muscular than the right ventricle wall?

The heart has 2 sides; the left and the right. The left side of the heart pumps oxygenated blood from the lungs to supply the rest of the body. The right side of the heart pumps deoxygenated blood from the body to the lungs. Much more pressure is needed to pump the blood from the left ventricle into the body than is needed to pump blood the short distance from the right ventricle to the lungs. As a result, the left ventricle has more muscle in order to create more force to pump the blood to the body, creating a thicker wall.