146 ORIGIN, INSERTION, AND USE 



Use. — They are more or less engaged in moving the os 

 hyoideus in different directions. 



GLOSSAL REGION. 



These muscles, by their union, compose that fleshy body 

 called the tongue. 



They are named genio-hyo-glossus, hyo-glossus longus, 

 hyo-glossus brevis, and lingualis. 



MAXILLARY REGION 



Comprehends three strong and well-defined muscles. 



1. The masseter. 



Origin. — From the under part of the zygomatic arch, and 

 from the superior maxillary bone. 



Insertion. — Into the rough border, around the angle of the 

 jaw. 



Use. — To act, in conjunction with the temporalis, in the 

 elevation of the jaw. 



2. The stylo-maxillaris. A round and compact muscle, 

 found above and behind the jaw. 



Origin. — From the styloid, or coronoid process. 



Insertion. — Into the angle of the jaw. 



Use. — To pull the jaw backwards, and depress it. 



3. The pterygoid eus.- It takes the same course inwardly, 

 to what the masseter does outwardly. 



Use. — To close the jaws. It also gives a lateral motion 

 to the jaws. 



PHARYNGEAL REGION 



Comprehends six pairs of muscles, belonging to the 

 pharynx. They are named as follows : — 



Hyo-pharyngeus, Constrictor pharyngeus inferior. 



Palato-pharyngeus, " " superior. 



Stylo-pharyngeus, " " medius. 



Use. — To dilate and contract the pharynx. 



