 Dear students, in this topic, we shall discuss the work done by the heart. You know that in physics, work is defined as the product of force and distance. For the heart, work is to move a volume of blood. So for heart, work is equal to the product of volume of blood moved and the pressure required to move it. Now in this calculation, volume is taken as the stroke volume. That is, the volume of blood that is ejected during one ventricular contraction and the ventricular pressure is taken as the mean arterial pressure. So work done by the heart during one stroke, that is, stroke work is the product of stroke volume and mean arterial pressure MAP. Dear students, work done by the two ventricles, that is, right and left, is not equal. It differs. Although, both ventricles eject equal volume of blood, but right ventricle pumps blood in pulmonary circuit, which is a comparatively shorter circuit. In this comparison, left ventricle pumps blood into the systemic circuit, which is quite large and extensive. So as a result, the pressure generated by the right ventricle is much lower. If we look at the calculation wise, then when the pressure is less generated, the external work done by the right ventricle is much less. The pressure generated by left ventricle is much higher because it pumps blood in an extensive systemic circuit. Now the greater work is done by this ventricle.