chorda tendinea

noun

chorda ten·​din·​ea -ˌten-ˈdin-ē-ə 

plural chordae tendineae -ē-ˌē 

: any of the delicate tendinous cords that are attached to the edges of the atrioventricular valves of the heart and to the papillary muscles and serve to prevent the valves from being pushed into the atrium during the ventricular contraction