Inside the ventricle. Chordae attach the valve to its papillary muscles. They are located on the ventricular side of the valve.
Heart. This id the structure that holds the heart valves in place - on thae right side is called tricuspid valve and left side mitral valve these valves are attached ti inside the heart chamber to the walls via papillary muscle. This chordate structure holds the valve in place like a bicycle spoke wheel attachment from the center of the wheel to the tires-rim assembly.
Below. The chordae tendinae are attached to the underside of the tricuspid (right side of the heart between the right atrium and right ventricle) and the mitral valve (left side of the heart between the left atrium and left ventricle). The attach much the same way that the chords of a parachute attach to the chute. The transmit the forces to pull open the valve and align it to close properly.
Chordae. The chordae are support structures for the mitral and tricuspid valves. When they are damaged, valvar insufficiency results. This can be severe enough to cause congestive heart failure either acute or chronic.