130 SPECIAL ANATOMY. 



163. 2. Buccinator, cheek muscles. 



Fig.: oblong, broad, flat. Pos.: between upper and lower jaw; 

 behind covered by the ramus of the lower jaw, masseter and tem- 

 poralis ; before by zygomalid, risorius ; perforated by duct. 

 Stenonian. (opposite the three superior molar teeth) ; covered in- 

 ternally by the buccal mucous membrane. Or. : 1. Over the last 

 molar tooth. 2. Hamulus of proc. pterygoid. 3. Mveolus of 

 the upper and lower jaws. Ins.: sphincter oris. Act.: draws 

 the angles of the mouth outwards; contracts the buccal cavity (in 

 whistling, blowing). 



Nerves : buccinator, buccales, facialis. 



164. 3. Levator labii superioris alseque nasi, 



(Pyramidalis of Theile.) 



Fig. : flat, divided below. Pos. : on the side of the nose, some- 

 what covered above, by sphincter palpebr., then, below, by the 

 skin, above, compressor and depressor alae nasi. Or. : proc. frontal. 

 of upper jaw to Kg. palpebr. intern. Ins.: the stronger portion 

 to sphincter oris, the weaker to the ala nasi. Act. : elevates the 

 ala nasi, corrugates the nasal membrane, and raises the upper lip 

 at the same time. 



165. 4. Levator labii superioris proprius s. Incisorius. 



Fig. : flat, four-sided, broader above. Pos. : covered above by 

 sphinct. palpebr., then only by the skin on the external border of 

 this muscle, on the inner of the zygomatic minor, with which it 

 is united below. Or. : aboveybram. infraorbitale. Ins. : sphincter 

 oris and skin of upper lip. Act. : elevates the upper lip. 



166. 5. Levator anguli oris (s. Caninus). 



Pos. : vertical ; external to the one last described ; covered by 

 it, below free. Or. : half an inch below foram. infraorb., broad. 

 Ins. : sphincter oris, depressor labii inferior. Act. : raises the 

 angle of the mouth somewhat inwards. 



167. 6. Zygomaticus minor, small zygomatic muscle, 



sometimes wanting. 



Pos. : oblique, at commencement covered by orbic. palpebr., 

 upon the last described, free beneath the skin. Or. : os zygo- 

 matic. Ins. : the upper lip ; mingling with levator labii prop. 

 Act. : raises the upper lip and draws it somewhat outwards. 



