ORGANS OF PREHENSION. 225 



press the angle of the mouth, and antagonize the leva- 

 tor. 



Levator Idbii inferioris (or menti) is seen by turning down 

 the lower lip and lifting the mucous membrane. It arises, 

 on either side of the frenum, from the surface in front of 

 the alveoli of the incisor teeth of the lower jaw; its fibres 

 descend and are inserted into the integument of the chin. 

 Its function is to elevate the chin and lower lip. 



Depressor labii inferioris (quadratics menti) is a broad 

 muscle intermixed with fat, and situated upon either side 

 of the symphysis. It arises from the side and front of the 

 inferior maxilla at its base, and is inserted into the greater 

 part of the lower lip and orbicularis muscle. Its function 

 is to depress the lower lip. 



Zygomaticus major is a long, slender muscle, and arises 

 from the malar bone near the zygomatic suture. It is in- 

 serted into the angle of the mouth. Its function is to draw 

 the mouth upwards and backwards, as in smiling. 



Zygomaticus minor is very small. It arises from the 

 malar prominence, and is inserted into the upper lip near 

 the angle. This muscle is sometimes wanting, and some- 

 times it is simply a slip of the orbicularis palpebrarum by 

 which its origin is covered. Its function is the same as that 

 of the zygomaticus major. Both these muscles blend with 

 the others which are inserted into the angle of the mouth. 



Buccinator (fiovxavov, a trumpet,) is situated at the side 

 of the face, between the upper and lower jaws. It is a thin 

 and broad sheet of muscle, the fibres of which run horizon- 

 tally, and arise from the alveoli of the last molar teeth of 

 the upper jaw, as far back as the pterygoid processes; from 

 the external oblique ridge of the lower jaw, as far back as 

 the coronoid process, and from the pterygo-maxillary liga- 

 ment. It is inserted into the angle of the mouth and blends 

 with all the other muscles inserted here. Its function is to 

 retract the lips, to diminish the cavity of the mouth by 

 drawing the cheek to the teeth, thus aiding in mastication; 

 and to assist to puff out the cheek, as in filling wind instru- 

 ments. It is covered by a quantity of fat, found in soft, 

 15 



