why does the ventricles have thick walls than atria
Ventricle (heart) Ventricles have thicker walls than atria and generate higher blood pressures. The physiological load on the ventricles requiring pumping of blood throughout the body and lungs is much greater than the pressure generated by the atria to fill the ventricles. Further, the left ventricle has thicker walls than the right because it needs to pump blood to most of the body while the right ventricle fills only the lungs.
Atrium (heart) The atrium is the upper chamber in which blood enters the heart. There are two atria in the human heart, which receive blood â€“ the left atrium from the lungs, and the right atrium from the venous circulation. The atria receive blood, and when the heart muscle contracts, pump blood to the ventricles. All animals with a closed circulatory system include at least one atrium / auricle (humans have two atria).