The wall of the left ventricle is much thicker than that of the right ventricle because it
- A. holds a far larger volume of blood
- B. must pump blood against the much greater resistance of the systemic circuit
- C. contains more valves than the right ventricle
- D. receives blood at a higher pressure from the left atrium
Explanation
Both ventricles eject the same volume with each beat, but the left has to drive blood through the whole body while the right only sends it to the lungs a short distance away and at low pressure. More cardiac muscle means a higher pressure can be generated, which is why the left wall is roughly three times thicker. Blood enters both ventricles from the atria at low pressure.