What are the cords that hold two heart valves in place?

The cords holding the two heart valves in place are called chordae tendineae. They are thin, collagenous cords that attach the papillary muscles of the ventricles to the cusps of the heart valves. These cords prevent the valves from prolapsing into the ventricles during ventricular systole, allowing blood to flow efficiently from the ventricles to the pulmonary artery and aorta.