Each ventricle has an inflow part beginning just in front of the corresponding atrioventricular orifice and running forwards to the left towards the apex of the heart. The cavity turns upwards to form the outflow part. The inflow part of each ventricle has a

rough inner surface because of trabaculae carneae which are bundles of muscle fibers. The wall also has fingerlike processes attached to the ventricular wall at one end and free at the other. These are called papillary muscles. These are functionally related to the atrioventricular valves.

In contrast to the rough wall of the inflow parts, the outflow part of the two ventricles are smooth. The out flow part of the right ventricle is called the infundibulum. It leads to the pulmonary trunk separated by the pulmonary valve. The inflow and outflow parts make an angle of about 90 degrees with each other. The upper part of their junction is marked by a prominent bulging of the myocardium called the supraventricular crest. The outflow part of the left ventricle is called the aortic vestibule. It leads to the ascending aorta separated by the aortic valve. The aortic vestibule forms an acute angle with the inflow path, running sharply upwards and to the right to reach the aortic orifice. It crosses behind the infundibulum from left to right. This explains how the aortic orifice comes to lie to the right of the pulmonary orifice. A large part of the left ventricle is overlapped in front by the right ventricle.  

The wall of the left ventricle is much thicker than the wall of the right ventricle. The outline of the left ventricle is roughly circular. In contrast the cavity of the right ventricle is crescentic in outline. This is because of the fact that the interventricular septum bulges into the right ventricle so its right surface is convex, and its left surface is concave.