Dictionary.net

any of several muscles associated with the atrioventricular valves; "the papillary muscles contract during systole to prevent regurgitation of blood into the atria"

any of several muscles associated with the atrioventricular valves; "the papillary muscles contract during systole to prevent regurgitation of blood into the atria"

Conical muscular projections from the walls of the cardiac ventricles, attached to the cusps of the atrioventricular valves by the chordae tendineae.