182 



MUSCLES OF THE HEAD AND NECK. 



backwards and outwards, and is inserted into the angle and the inner 

 surface of the ramus of the jaw as high as the dental foramen. 



Between the external surface of the muscle and the ramus of the maxilla are the 

 internal lateral ligament and the internal maxillary vessels, with the dental artery 

 and nerve ; and at its upper part the muscle is crossed by the external pterygoid 

 muscle. Its inner surface, whilst in the pterygoid groove, is in contact with the 

 tensor palati muscle ; and lower down it corresponds with the superior constrictor of 

 the pharynx. 



Fig. 158. 



Fig. 158. VIEWS OP THE PTERYGOID MUSCLES A, FROM THE OUTER SIDE ; B, FROM 



THE INNER SIDE. 



1, external pterygoid, placed on the upper head in A, on the lower head in B ; 2, 

 internal pterygoid the outer surface in A, the inner surface in B. 



Fig. 159. VIEW OP A DISSECTION OF THE 



LOWER PART OF THE SKULL AND FACE, 

 FROM BEHIND, DESIGNED TO SHOW THK 

 ATTACHMENTS OF THE PTERYGOID AND 



SOME OTHER MUSCLES (modified from 

 Bourgery). 



a, placed above the transverse section 

 of the basilar part of the occipital bone, 

 below which are seen the posterior nares 

 and palate ; 6, transverse section through 

 the temporal bone ; c, roof of the mouth ; 

 d, back of the head and neck of the 

 lower jaw, above which are seen the 

 syuovial cavities of the joint divided by 

 the interarticular fibro-cartilage ; e, 

 placed below the symphysis menti ; 1, ou 

 the left side the internal pterygoid muscle 

 entire ; 1', on the right side the lower part 



of the same muscle, of which the middle portion has been removed to show the external 

 pterygoid ; 2, the lower thick portion of the external pterygoid ; 2', on the right side 

 points to the upper smaller portion of the muscle, attached in part to the interarticular 

 plate ; 3, is placed at the side of small portions of the genio-hyoid and genio-hyo- 

 glossus muscles cut short at their attachment to the lower and upper genial tubercles ; 4, 

 the attachment of the mylo-hyoid muscle cut short ; 5, indicates the attachment at the 

 side of the symphysis of the anterior belly of the digastric muscle ; 6, the masseter 

 muscle descending to the angle of the jaw. 



The external pterygoid muscle, occupying the zygomatic fossa, arises by 

 two fleshy heads placed close together, the superior of which is attached to 



