Heart in a Lateral Cross Section

Description

Cut through the cardiac silhouette in a lateral cross section and the left and right ventricles dominate the field, separated by the interventricular septum and capped superiorly by portions of the atria. The left ventricular free wall appears markedly thicker than the right ventricular wall, with the left ventricular cavity positioned more posteriorly and to the left, and the right ventricle lying more anteriorly. Portions of the mitral valve apparatus are visible at the left atrioventricular junction, including valve leaflets tethered by chordae tendineae to papillary muscles projecting from the ventricular myocardium. On the external surface, the ascending aorta and pulmonary trunk arise superiorly, and the coronary arteries course in the atrioventricular and interventricular grooves with accompanying cardiac veins. A lateral section is one of the clearest ways to teach why the left ventricle develops concentric hypertrophy in systemic hypertension or aortic stenosis, while the right ventricle dilates and thins under chronic pulmonary hypertension. Wall thickness is the story. Seeing the chordae and papillary muscles in situ also supports discussions of acute mitral regurgitation after papillary muscle rupture, a classic post infarction complication involving the posteromedial papillary muscle supplied by the posterior descending artery. Use this asset in cardiothoracic anatomy teaching for medical and PA curricula, in echocardiography and cardiac MRI primers that correlate short axis and long axis planes with gross morphology, or in clinical education materials explaining ventricular remodeling, valvular insufficiency, and coronary artery distribution. It also fits surgical overviews of mitral valve repair, ventricular septal defect location, and the spatial relationship of the aortic root to the left ventricular outflow tract. Anatomical accuracy verified by SciePro's Medical Advisory Board.