The walls of ventricles are much thicker than atria. Explain.

(N/A) The walls of the ventricles are thicker because they are responsible for pumping blood forcefully into different parts of the body,which requires higher pressure.
The wall of the left ventricle is significantly thicker (about three times) than that of the right ventricle because it must pump blood to the entire systemic circulation,whereas the right ventricle only pumps blood to the lungs.