Final answer:
The intermediate zone of the TMJ is the region occupied by the articular disc, which is situated between the mandibular condyle and the temporal bone's mandibular fossa and articular tubercle, facilitating smooth movements and acting as a shock absorber during jaw motions.
Step-by-step explanation:
The intermediate zone of the temporomandibular joint (TMJ) refers to the area where the articular disc separates the two bony components of the joint: the mandibular condyle and the temporal bone's mandibular fossa and articular tubercle. The articular disc is a flexible structure that enables smooth movements and serves as a cushion between the bones during various motions such as opening, closing, and lateral movements of the jaw.
The TMJ is a complex joint that allows for the elevation (closing of the mouth), depression (opening of the mouth), protraction, retraction, and side-to-side movements of the mandible. The articular disc within the TMJ plays a crucial role in facilitating these movements by providing a smooth gliding surface and acting as a shock absorber. In particular, during the opening of the mouth, the TMJ undergoes a combination of hinging and gliding motions, where the mandibular condyle and the associated articular disc move forward and downward from the mandibular fossa onto the articular tubercle.