More force is required to pump blood through the body than through the lungs, so the muscular wall of the left ventricle is thicker than the right.
Interatrial, interventricular, and atrioventricular septa separate the four chambers of the heart (Fig. 3.69B). The internal anatomy of each chamber is critical to its function.
In the anatomical position, the right border of the heart is formed by the right atrium. This chamber also contributes to the right portion of the heart’s anterior surface.