Final answer:
The left ventricle exerts greater force upon contraction, given its thicker myocardium and the higher pressure required to pump blood through the systemic circuit compared to the right ventricle's role in the pulmonary circuit.
Step-by-step explanation:
Of the two ventricles, the left ventricle exerts greater force upon contraction. The left ventricle must generate a much greater pressure to overcome the greater resistance found in the systemic circuit, as opposed to the right ventricle which pumps blood into the shorter, less resistant pulmonary circuit. The muscular wall of the left ventricle, or myocardium, is significantly thicker in order to cope with this demand, therefore, it exerts more force during contraction.
During ventricular systole, particularly the ventricular ejection phase, the left ventricle's contraction creates higher pressure within the ventricle than the pressure in the pulmonary trunk and the aorta, driving blood throughout the body. Despite their different pressures, both ventricles pump the same volume of blood, known as stroke volume, ranging between 70-80 mL. Figure 19.8 illustrates these differences in muscle thickness and force of contraction between the two ventricles.