190 



Anatomy of Skeleton 



starting at the root of the nose ; this is termed the metopic suture, and is an indication 

 of the fact that the bone develops in two halves which subsequently fuse. The facial 

 bones, which form the floor of the orbits, come up to articulate with the frontal at each 

 side of the openings of -these cavities, so that the frontal bone affords support to the 

 bones of the face : the external column of support is the prominent external angular 

 process of the frontal. 



We can now appreciate the position of the bones seen on the lateral aspect of the 

 skull (Fig. 160). 



Looking at it from the side, we see that the lower border of the parietal bone arti- 

 culates along a curved suture with a plate of bone that is part of the temporal bone, 

 known as the squama, or squamous portion of the temporal, and from the lower part 

 of this an arched process extends forward to join a corresponding backward extension 

 from one of the face bones. The arch made in this way is the zygomatic arch, and the 



toeitdr. 



FIG. 160. Skull from the side without lower jaw. The stippled 

 part is the temporal fossa. The inferior temporal crest is 

 under cover of the zygoma. 



temporal process is the zygomatic process, or zygoma. The temporal articulates with the 

 whole extent of the lower border of the parietal, tracing it backwards, thus reaching 

 the end of the lambdoid suture, where it comes into relation with the occipital bone, 

 and the suture between the two turns on to the base of the skull. The back and lower 

 part of the temporal, articulating with the back part of the lower border of the parietal, 

 is easily distinguished by its appearance from the squama, and is continued down as 

 a blunt projection, the mastoid process. 



In front of the temporal another bone is seen separating the squama from the frontal 

 and articulating above with the lower front angle of the parietal : this is the outer 

 surface of the great wing of the sphenoid. 



The sphenoid is a bone that properly belongs to the base of the skull, where it has 

 a body that lies centrally, but two pairs of " wings " project out from this body, and 

 of these the greater wings form part of the skull base out to the sides, and a\so help 

 in forming part of the side walls : here each wing articulates with the squama behind, 



