The<unk><unk>  of the<unk> , directed downward and slightly backward, is formed by the ventricles, and rests upon the central tendon and a small part of the left muscular portion of the diaphragm.
It is separated from the base by the posterior part of the coronary sulcus, and is traversed obliquely by the posterior longitudinal sulcus.
Diaphragmatic surface of heart
Left margin of heart
Apex of the heart
Right border of heart
Sternocostal surface
Mediastinal surface of lung
Serous pericardium
Floating rib