There are two valves separating the ventricles from the atria. They are called atrioventricular valves. On the right side, it is the tricuspid valve, and on the left side it is the mitral valve.
The valvular apparatus
One of these valves is found in each ventricle. It is made up of a fibrous ring, leaflets, attachments called chordae and muscular “pillars” called papillary muscles, which are found in the ventricles.
These valve elements all together form a 3-dimentional functional unit called valvular apparatus, which is more complex than the two other valves of the heart (the aortic and the pulmonary valves)
The mitral valve apparatus
One can compare the mitral valve apparatus to a sailing ship. We have the mast, the sails and the ropes which connect them to the structure.
The two layers are attached around the fibrous ring. The edge of these leaflets extend into a configuration that looks like a net. This net structure then leads to small tendons that look like short ropes. These ropes are then attached to small muscle pillars at the bottom of the left ventricle.