Final answer:
In the temporomandibular joint (TMJ), the space above the fibrous disc is known as the superior joint cavity, and the space below is the inferior joint cavity. These cavities are crucial for the movement and lubrication of the joint.
Step-by-step explanation:
The spaces above and below the fibrous disc of the temporomandibular joint (TMJ) are involved in the movement of the mandible during activities such as chewing and talking. The fibrous disc of the TMJ is located between the condyle of the mandible and the mandibular fossa and articular tubercle of the temporal bone. When the mouth opens, the mandible and the disc glide forward from the mandibular fossa onto the articular tubercle, which results in the forward and downward motion required for mandibular depression.
The space located above the fibrous disc is the uperior joint cavity, and the space below it is the inferior joint cavity. These spaces allow for the distribution of synovial fluid, which lubricates the joint, and provide room for the disc to move as the jaw opens and closes.