DISSECTING MANUAL. 



Muscles of Mastication. 



Masseter. Origin; inner surface and anterior two-thirds 

 of lower border of zygoma. Insertion ; outer surface of ramus 

 of lower jaw and coronoid process. [407] 



Temporal. Origin; whole temporal fossa; temporal fascia. 

 Insertion; anterior border of ramus and deep surface of coro- 

 noid process of lower jaw. [408] 



External Pterygoid. Origin; (upper head) under surface 

 of great wing of sphenoid ; (lower head) outer surface of ex- 

 ternal pterygoid plate. Insertion; a depression in front of 

 neck of lower jaw; inter- articular fibre-cartilage and capsule 

 of temporo-maxillary joint. [408] 



Internal Pterygoid. Origin; deep surface of external 

 pterygoid plate; tuberosity of upper jaw. Insertion; trian- 

 gular impression on inner surface of lower jaw, between the 

 angle and my lo- hyoid groove. [410] 



Muscles of Neck. 



Sterno-cleido-mastoid. Origin; (sternal head) anterior sur- 

 face of manubrium sterni; (clavicular head) upper surface of 

 inner third of clavicle. Insertion; mastoid process; superior 

 curved line of occipital. [410] 



Muscles of Hyoid Bone. 



Omo-hyoid. Origin (posterior belly); superior border of 

 scapula; suprascapular ligament. Course; forward and up- 

 ward to an intermediate tendon, and then upward. Insertion 

 (anterior belly) ; body of hyoid bone. [411] 



Sterno-hyoid. Origin; back of presternum and first costal 

 cartilage; clavicle. Insertion; body of hyoid internal to pre- 

 ceding. [411] 



Sterno-thyroid. Origin; back of presternum and first cos- 

 tal cartilage. Insertion; oblique line of thyroid cartilage. It 

 has a tendinous intersection. [412] 



[62] 



