Why is the wall of the ventricle thicker than the wall of the aria?

The wall of the ventricle is thicker than that of the atria because the ventricles are responsible for pumping blood throughout the body and must generate higher pressure to do so. In contrast, the atria only need to receive blood and push it into the ventricles, requiring less muscular force. This structural difference reflects their distinct roles in the circulatory system, with the ventricles designed for powerful contractions.