130 MUSCLE TISSUE 



Zygomaticus Minor. Origin, malar bone; inserted 

 into skin and fascia of upper lip internal to angle of 

 mouth and the insertion of the zygomaticus major; 

 fuses with fibers of orbicularis oris. Action draws the 

 upper lip backward, upward, and outward, thus gives 

 to the face an expression of sadness. Nerve, facial. 



The Muscles of the Chin and Lower Lip (Mandibular 

 Region) 



Levator menti. 

 Depressor anguli oris. 

 Depressor labii inferioris. 



Levator Menti. Origin, mandible external to sym- 

 physis; inserted into skin of chin. Action raises lower 

 lip, wrinkles chin, gives to the face the expression of 

 doubt, disdain, and pouting. Nerve, facial. 



Depressor Anguli Oris. Origin, from mandible, in- 

 serted into angle of mouth. It is blended with the 

 platysma, orbicularis oris, risorius, and levator anguli 

 oris. Action depresses angle of mouth. Acting with 

 the levator anguli oris the two will depress angles of 

 the mouth directly inward, as in smirking. Nerve, 

 facial. 



Depressor Labii Inferioris. Origin from mandible; 

 insertion, skin of lower lip, blends with fibers of orbicu- 

 laris oris and muscle of opposite side. Action depresses 

 lower lip. Nerve, facial. 



The Muscles of the Buccal Region 



Orbicularis oris. 



Buccinator. 



Risorius. 



Orbicularis Oris. This is the muscle of the mouth 

 and lips. It consists of oblique and transverse fibers 



