86 ELEMENTAR Y ANA TOM Y. [LESS. 



spoken of already as medianly dividing the posterior nasal 

 openings. In the infant this bone consists of two lateral 

 portions. 



The inferior turbinate bones, or lowest TURBINALS, extend 

 (one on each side) from before backwards along the nasal 

 fossae, attached, though but slightly, to the inner side of the 

 maxillary and palatine bones. 



12. The only naturally separated bone of the skull in the 

 adult, namely the lower jawbone, or MANDIBLE, consists ot 

 a curved osseous band, almost of the same depth through- 

 out, and convex forwards. It has a smooth rounded inferior 

 edge, but its upper edge is festooned by unequal cavities, 

 forming sockets for the teeth, whence this upper border 

 is termed " alveolar." The whole band is termed the body 

 of the mandible ; a vertical line at its middle in front is 

 called the syinphysis? and each half of the body external to 

 this line is called the horizontal ramns (or branch). At its 

 hinder end each horizontal ramus turns suddenly upwards at 

 a slightly obtuse angle, and terminates above in two processes, 

 the front one of which is pointed and is called the " coronoid 

 process? while the hinder one ends in a rounded head, " the 

 condyle" mounted on a narrower part termed the " neck" 



This nearly vertical part on each side is called the ascend- 

 ing ramus, and the point where its posterior margin meets 

 the inferior margin of the horizontal ramus is named the 

 "angle." (Fig. 83.) 



The condyle is wider than it is long, and fits into the glenoid 

 cavity of the squamous part of the temporal bone. An inter- 

 articular fibre-cartilage (with one synovial sac above it and 

 one below it) is interposed between the two bones, and the 

 ascending ramus is also attached to the skull by strong 

 ligaments. 



The coronoid process rises nearly as high as the condyle, 

 and has inserted into it the temporal muscle which adheres, 

 at its origin, to the side of the skull within the arch of the 

 zygoma. 



On the inner side of the ascending ramus is a foramen, 

 called the inferior dental, and another, the mental foramen, 

 is placed, more forwards, on the outer side of the horizontal 

 ramus. 



The symphysis is concave vertically in front, the lower 

 border of the mandible projecting at the symphysis to form 

 the chin. 



1 From o-i'/i^oyUf, to grow together. 



