Which anatomical structure surrounds the TMJ and provides lubrication?

The anatomical structure that surrounds the temporomandibular joint (TMJ) and provides lubrication is synovial fluid. This viscous fluid is produced by the synovial membrane, which lines the joint capsule of the TMJ. Synovial fluid plays a crucial role in reducing friction between the moving surfaces of the joint during activities such as chewing and speaking. It also acts as a nutrient source for the avascular cartilage that covers the ends of the bones in the joint, aiding in joint health and mobility.

While cartilage does contribute to the structure of the joint by providing a smooth surface for movement, it does not function as a lubricant. Bone forms the rigid structure of the TMJ but is not involved in lubrication either. Muscle tissue contributes to the movement of the jaw and stabilization of the joint but serves a different function than that of synovial fluid in terms of lubrication. Thus, synovial fluid is essential for the proper functioning and maintenance of the TMJ.