This illustration demonstrates an anterior view of the thoracic cavity, highlighting the position of the heart in relationship to the ribs and diaphragm. The right atrium, right ventricle, and a small portion of the left ventricle are visible from this aspect. Note that in the majority of cases, 2/3 of the heart is positioned to the left of midline with the inferior aspect resting on the diaphragm. The apex of the heart is pointing inferiorly and to the left, causing the long axis of the heart to be at an acute angle to the long axis of the body.