LATERAL REGION OF THE SKULL. 



105 



LATERAL EEGION OF THE SKULL. 



The Lateral Region of the Skull is somewhat of a tria-ngular form, its oase being 

 formed by a line extending from the external angular process of the frontal bone 

 along the temporal ridge backwards to the outer extremity of the superior curved 

 line of the occiput : and the sides being formed by two lines, the one drawn 

 downwards and backwards from the external angular process of the frontal bone 

 to the angle of the lower jaw, the other from the angle of the jaw upwards and 

 backwards to the extremity of the superior curved line. This region is divisible 

 into three portions, temporal, mastoid, and zygomatic. 



Fig. G4. Side View of the Skull. 



Frontal 



THE TEMPORAL FOSS.E. 



The Temporal fossa is bounded above and behind by the temporal ridge, which 

 extends from the external angular process of the frontal upwards and backwards 

 across the frontal and parietal bones, curving downwards behind to terminate at 

 the root of the zygomatic process. In front, it is bounded by the frontal, malar, 

 and great wing of the sphenoid : externally, by the zygomatic arch, formed 

 conjointly by the malar and temporal bones; below, it is separated from the 

 zygomatic fossa by the pterygoid ridge, seen on the outer surface of the great 

 wing of the sphenoid. This fossa is formed by five bones, part of the frontal, 

 great wing of the sphenoid, parietal, squamous portion of the temporal, and malar 

 bones, and is traversed by five sutures, the transverse facial, coronal, spheno 

 parietal, squamo-parietal, and squamo-sphenoidal. It is deeply concave in front, 

 convex behind, traversed by grooves for lodging branches of the deep temporal 

 arteries, and filled by the Temporal muscle. 



