THE TEMPORAL BONE 



81 



The zygomatic process is connected to the temporal bone by three divisions, 

 called its roots an anterior, middle, and posterior. The anterior, which is short, 

 but broad and strong, is directed inward, to terminate in a rounded eminence, 

 the eminentia articular is. This eminence forms the front boundary of the 

 glenoid fossa, and in the recent state is covered with cartilage. The middle 

 root (postglenoid process) forms the posterior boundary of the mandibular portion 

 of the glenoid fossa; while the posterior root, which is strongly marked, runs from 

 the upper border of the zygoma, in an arched direction, upward and backward, 

 forming the posterior part of the temporal ridge (supramastoid cresf). At the 

 junction of the anterior root with the zygoma is a projection, called the tubercle, 

 for the attachment of the external lateral ligament of the mandible; and between 



Groove for middle 

 temporal artery 



Incisura parietalis 



Suprameatal 

 triangle 



OCCIPITO- 

 FRONTALIS 



Eminentia 

 articulari, 

 Postglenoid process 



Glenoid cavity 



Glaserian fissure 



Tympanic plate 



STYLOGLOSSUS 



Occipital groove 



External auditory process 



TYLOHYOIO 



^Styloid process 



FIG. 47. Left temporal bone. Lateral surface. 



the anterior and middle roots is an oval depression, forming part (mandibular) 

 of the glenoid fossa, for the reception of the condyle of the mandible. Between 

 the posterior wall of the external auditory meatus and the posterior root of the 

 zygoma is the area called the suprameatal triangle (Macewen), often marked by 

 a spinous process. 



The internal surface of the squamous portion (Fig. 48) is concave, presents 

 numerous eminences and depressions for the convolutions of the cerebrum, and 

 two well-marked grooves for the branches of the middle meningeal artery. 



Borders. The superior border is thin, bevelled at the expense of the internal 

 surface, so as to overlap the lower border of the parietal bone, forming the 

 squamous suture. The anterior inferior border is thick, serrated, and bevelled, 



