Left Ventricle Papillary Muscles, Lateral View

Description

Viewed from the lateral aspect of the left ventricle, the endocardial surface of the ventricular chamber is opened in section to expose the papillary muscles projecting from the ventricular wall. The anterolateral papillary muscle sits more anterior and lateral, while the posteromedial papillary muscle lies more inferior and medial, each giving rise to chordae tendineae that course superiorly to the mitral valve leaflets at the atrioventricular junction. Trabeculae carneae ridge the surrounding myocardium, and the epicardial surface externally corresponds to the subserosa where the larger coronary vessels run in the atrioventricular and interventricular grooves. Clear spatial orientation matters here. This lateral perspective is the workhorse view for teaching why papillary muscle integrity determines mitral competence: the chordae restrain leaflet prolapse during systole, and rupture or dysfunction produces acute mitral regurgitation with a characteristic posteriorly directed jet when the posteromedial papillary muscle fails. Single-coronary supply makes the posteromedial papillary muscle more vulnerable after inferior myocardial infarction (often right coronary artery or dominant circumflex territory), while the anterolateral muscle usually benefits from dual supply from diagonal and obtuse marginal branches. Surgeons and echocardiographers both think in this geometry when correlating wall motion abnormalities to valve behavior. Use this artwork in gross anatomy and cardiovascular physiology modules to anchor the mitral apparatus, in cardiology texts discussing ischemic mitral regurgitation and papillary muscle rupture, and in surgical education for mitral valve repair planning and ventricular reconstruction. It also pairs well with pathology and imaging figures in which a lateral left ventricular section explains papillary muscle displacement in dilated cardiomyopathy. Anatomical accuracy verified by SciePro's Medical Advisory Board.