70 



NECK. 



Pterygoideus externvs}— Origin, from the pterygoid, spinous and 

 p- 5g temporal processes of the sphenoid, 



and from the tuber of the upper max- 

 illary bone. Ifisertion, into the neck 

 of the lower jaw. Use; draws the 

 jaw forwards. 



Pterygoideus internus? — Ori- 

 gin, from the internal pterygoid 

 process, pterygoid fossa of the 

 sphenoid, and from the Eustachian 

 tube. Insertior}, into the internal 

 surface of the angle of the jaw. 

 Use; draws the jaw upwards and 

 inwards. 



MUSCLES OF THE NECK. 



FascicL. — There are two fascioe for the neck ; the superficial and 

 deep. 



The superficial fascia is continuous with that which covers the 

 whole body. It consists of two laminae, between which are en- 

 closed the platysma myoides muscle. 



The deej? fascia is formed of more condensed cellular tissue, and 

 extends from the ligamentum nuchce to the larynx in front, including 

 between its laminse the sterno-cleido-mastoid muscles, and vessels 

 of the neck. A strong process of it exists between the styloid pro- 

 cess of the temporal bone and the angle of the jaw, and is called the 



stylo-maxillary liga- 

 ^ig-^~- ment. Inferiorly, it 



forms a loop, which 

 acts as a pulley to 

 the omo-hyoid muscle, 

 and thence is, con- 

 tinued down behind 

 the subclavius muscle 

 into the ligamentum 

 bicorne, forming a por- 

 tion of the boundary 

 of tlic thorax. 



Plati;S7ua myoides, 

 is included between 

 two laminre of the 

 superficial fascia of the 

 neck, is a broad, thin 

 muscle, and not al- 

 ways well developed 

 in man. Origin, from 

 the condensed cellu- 



