There are normally two papillary muscles. The antero-lateral papillary muscle is located in the apical third of the ventricular wall, and the postero-medial papillary muscle is located in the middle third of the ventricular wall. The antero-lateral papillary muscle is usually composed of one body or head, and the postero-medial papillary muscle usually with two bodies or heads. Each papillary muscle provides chordae to both leaflets of the mitral valve, with one of the major functions of the papillary muscles being to prevents prolapse of anterior and posterior cusps of mitral valve during systole.