382 THE MUSCULAR SYSTEM. 
maxillary artery passes over or under the muscle, and disappears between its two 
heads of origin. 
The internal pterygoid muscle has likewise a double origin—(1) from the deep 
Epicranial 
aponeurosis 
TEMPORAL MUSCLE 
Auriculo-temporal 
herve 
Posterior dental 
—— nerve 
—— 
Superficial temporal AN : vigsh = Z oS 
artery \ Y : : 
Buccal nerve 
Stenson’s duct 
EXTERNAL PTERYGOID—_ 
be 
Nerve to masseter ee a: 
“ —~ BuccrnaTor 
a MUSCLE 
Parotid gland— ; 
MAssETER (cut)— 
Fic. 281.—Muvscies oF MasticaTion, DEEPER VIEW (zygoma and masseter muscle removed). 
surface of the external pterygoid plate, and (2) by a stout tendon from the 
tuberosity of the upper jaw. It is quadrilateral in form, and is directed downwards 
Epicranial aponeurosis: 
/ 
f 
TEMPORAL ae 
ete 
Temporal branch of 
buccal nerve 
\ Temporal branches of 
J inferior maxillary nerve 
Auriculo-temporal nerve 
Superficial temporal 
artery EXTERNAL PTERYGOID 
External carotid artery Poatarigeentalentery 
Internal lateral li . =~ yt Ay 
n Sal Bie on SN Ress SSS } eee posterior dental nerve 
Posterior auricularartery W \ ONG) a 
== HNN. SI | 
i ANT a nerve 
Lingual nerve x Buccal 
Pterygo-mandibular 
Mylo-hyoid nerve __———__ YW! po YN SS \ ie é ligament 
Parotid a Vy yp He =—S Ne 
LA, a . 
Z¥\¥ MK = G Mental branch of inferior 
Le dental nerve 
Inferior dental nerve —_ 
MASSETER (catia , 
Fic. 282.—PreryGorp REGION. 
outwards, and backwards, to be inserted into a triangular impression on the inner 
surface of the lower jaw, between the mylo-hyoid groove and the angle of the 
bone. 
