The left ventricular cavity is typically smaller in size compared to the right ventricular cavity. The wall of the left ventricle is indeed thicker than the wall of the right ventricle because the left ventricle is responsible for pumping oxygenated blood to the rest of the body, which requires more forceful contractions. The right ventricle, on the other hand, pumps deoxygenated blood to the lungs, which requires less force. Therefore, the left ventricle has a thicker muscular wall to accommodate the increased workload, while the right ventricle has a thinner wall in comparison.