Fig. 3 DETAILED FIGURE OF THE EXTERNAL AUDITORY MEATUS AND THE LOWER JAW JOINT
The external auditory meatus (2), as in Fig. 2, is cut across and partly enveloped by its cartilaginous support. The mandibular joint (17) reveals its two compartments and the disc that separates them. To the lower rounded-out bony end of the joint -the condyloid process of the mandible- in attached the short lateral pterygoid muscle (23) made up of an upper and a lower "head" Its action is to protrude the lower jaw and cooperate in chewing. Other important structures fill the spaces in this crowded region. One is the stem of the facial nerve (VII) which is seen embedded in the remnant of the parotid gland (3) wedged in between and behind the vertical "ramus" of the mandible (38 in Fig. 2, which is here removed) and the mastoid process (9) of the temporal bone. Another is the thick maxillary artery (26) whose branches supply with blood the temporal region and the upper jaw-bone or maxilla as well as most parts between the latter and the base of the skull. .