MYOLOGY. 53 



TRANS VERS ALIS NASI. 



Runs from one internal ala of nose to the other. 

 Action. — To dilate nostrils. 

 Nerve. — Facial. 



ANTERIOR INTERMEDIATE. 



Origifi. — Facial surface of pre-maxilla above incisors. 

 Insertion. — With maxillo-nasalis minor into inferior turbinated 

 bone. 



Action. — Dilation of anterior nasal entrance. 

 Nerve. — Facial. 



MAXILLO-LABIALIS. 



Origin. — Inferior maxilla behind last molar. 



Insertion. — Skin of lower lip. 



Action. — Depresses lower lip, or singly moves it laterally. 



Nerve. — Facial. 



POSTERIOR INTERMEDIATE. 



Origin. — Outer surface of inferior maxilla beneath incisors. 

 Ifisertiofi. — Into fibres of orbicularis oris. 

 Action. — Elevates lower lip. 

 Nerve. — Facial. 



MASSETER. 



Origin. — Zygomatic process of temporal. 

 Insertion. — Outer surface of ramus of jaw. 

 Action. — Elevator of jaw. 

 Nerve. — Inferior maxillary of fifth. 



TEMPORAL. 



Origin. — From temporal fossa, temporal fascia and outer border 

 of orbit. 



Insertion. — Coronoid process and ramus of inferior maxilla. 

 Nerve. — Buccal branch of fifth. 



EXTERNAL PTERYGOID. 



Oi'igin. — Under surface of sphenoid and pterygoid process. 

 Insertion. — Neck of condyle of maxilla. 



Action. — To pull inferior maxilla forward, alone to cause lateral 

 motion, as in grinding food. 

 Nerve. — Buccal branch of fifth. 



