Consider the mammalian heart. why is the muscular wall of the left ventricle thicker than that of the right ventricle? the left ventricle has more nerve endings for contraction, and more muscle mass must be there to accommodate the extra neurons. this difference stems from the fact that frogs have a thicker left ventricular muscle mass. the ventricle wall must be thicker to inhibit diffusion between the right and left ventricle. the left ventricle must contract with more force in order to send blood to the body's extremities.