The anterior papillary muscle is the largest and most constant papillary muscle, and arises from the anterior wall of the ventricle.
The posterior papillary muscle may consist of one, two, or three structures, with some chordae tendineae arising directly from the ventricular wall.
The septal papillary muscle is the most inconsistent papillary muscle, being either small or absent, with chordae tendineae emerging directly from the septal wall.