218 



THE MUSCLES. 



glands, whioli in part separate it from the buccal mucous membrane. The 

 external, covered by the skin, adheres to it in the most intimate manner, and 

 is found isolated from it only on the median line, at first by the aponeurotic 

 expansion of the supermaxillo-labiajis, then by a musculo-fibrous layer 

 analogous to that which forms the mento-labialis. 



By its internal face, the inferior fasciculus likewise responds to the buccal 

 mucous membrane, and to some salivary glands. By its external face, it 



Fi?. 110. 





SUPERFICIAL MUSCLES OF THE FACE AND HEAD. 



1, Temporo-auriculai'is externus, or attollens maximus ; 2, Levator palpebi'a3, or 

 corrugator supercilii ; 3, Temporo-auricularis internus, or attollens posterior ; 

 4, 5, Zygomatico-auricularis, or attolleas anterior ; 6, Orbicularis palpebrarum ; 

 7, Parotido-auricularis, or deprimens aurem ; 8, Parotid gland ; 9, Temporal, or 

 subzygomatic vein; 10, Ditto, artery, 11, 12, Superior and inferior maxillary 

 nerves; 13, Fascia of the masseter muscle; 14, Nasal bones; 15, Supernaso- 

 labialis, or levator labii superioris aljeque nasi ; 16, Supermaxillo-labialis, or 

 nasalis longus labii superioris; 17, External maxillary or facial artery; 18, 

 Facial vein ; 19, Supermaxillo-nasalis magnus, or dilatator naris lateralis ; 20, 

 Superior maxillary nerve ; 21, Zygomatico-labialis, or zygomaticus ; 22, Parotid, 

 or Stenon's duct ; 23, Masseter ; 24, Alveolo-labialis, or buccinator ; 25, Super- 

 maxillo-nasalis parvus, or nasalis brevis labii superioris; 27, Labial is, or orbicu- 

 laris oris ; 28, Maxillo-labialis, or depressor labii inferioris ; 29, Mento-labialis, 

 or levator menti. 



forma an intimate union with the cutaneous integument, like the superior 

 fasciculus. 



This muscle plays the part of a constrictor of the anterior opening of the 

 mouth, and has complex functions to perform in suction, the prehension of 

 food, and in mastication. 



2. Alveolo-labialis. (Fig. 110, 24.)- 



jSyrwmjrms.— Molaris externus et internus — Bourgeht. {Buccinator — Percivall. Leyh 

 divides this muscle into two portions; its superficial plane he designates the buccinator, 

 and the deep plane the molaris.) 



Preparation. — Proceed to the ablation of the masseter ; dissect the external surface of 

 the muscle, taking care of the risoiius Santorini and zygomaticus, which aro confounded 

 vfith it. Then divide -it iu the m:ddle, as far as the commissure of the lips; turn 

 down each strip on the jaws, and remove the mucous membrane, in order to study the 

 inner face of the muscle and the attachments of the superficial plane to the maxillary 

 bones. 



