Valve tendons are located in the heart. Valve tendons are there for the specific reason to stop blood from flowing backwards.
The tendons you are talking about are called the cordae tendineae not heart strings
These tendons are anchored to the wall of the ventricle by chordae tendinease, which prevent the valve from inverting. The chordae tendinae are attached to papillary muscles that cause tension to better hold the valve.
To prevent the valve from opening in the other direction when the ventricles contract - this way, the blood doesn't go back through where it came from.
The chordae tendineae, or heart strings, are cord-like tendons that connect the papillary muscles to the tricuspid valve and the mitral valve in the heart.
The atrioventricular valves are held in place by the chordea tendeae. These tendons are chord like structures that stiffen to close the valve.
Yes, fingers have tendons.
Tendons attach muscle to bone.
Tendons attach muscles to bones.
Tendons are attached to muscles.
Tendons do flex.