MUSCULAR SYSTEM. 29 



Description of voluntary muscle. — The masscter muscle is lo- 

 cated on the outer part of the cheek. Form, flat, broad, thick, 

 four sided. Origin, on the temporal and superior maxillary bones. 

 Insertion, on the outer surface of the inferior maxillary. Action, 

 elevates the lower jaw. Nerve supply, from a branch of the fifth 

 cranial nerve (trifacial). 



