Articular disk

An articular disc (or fibrocartilago interarticularis of lat joint disc ) is an intermediate joint disc composed of fibrocartilage and taut, parallelfasrigen connective tissue (similar to the menisci ), which usually divides the joint cavity into two separate chambers.

Joint discs are usually free of nerves and blood vessels, they are nourished by diffusion from the synovial fluid ( synovial fluid ).

Function

Joint discs have several tasks. They serve to increase the contact area between the hinge portions. Furthermore, they are like inequalities ( inconsistency ) of the articular surfaces and buffer in addition to weighing on the joint pressure from and distribute it. They also support the leadership of the condyle in the - pan.

Examples

Typical examples of joint discs are

• In the sternum - clavicular joint or sternoclavicular joint ( articulatio sternoclavicularis ) between the collarbone ( clavicle ) and chest (sternum )
• The acromioclavicular joint ( articulatio acromioclavicularis ) between the collarbone and shoulder blade (scapula )
• Between radius ( ulna ) and leg triangle and
• TMJ ( temporomandibular joint ) between the lower jaw ( mandible ) and the temporal bone ( temporal bone ).

While the first three are missing in most mammals, the articular disc is formed in the temporomandibular joint in all mammals. Disci has been around in fish, for example, on the upper jaw at Stachelflossern.