NASAL MUSCLES. 



165 



Origin. — It arises from the surface of tlie superior maxilla, at 

 its junction with the malar and lachrymal bones. 



Insertion. — The tendon passes to the extremity of the nose, 

 where, joining its fellow, it forms a radiating expansion, becoming 

 lost in the upper lip. 



Action. — It elevates and corrugates the uj)per lip, if acting 

 with its fellow ; if acting alone, it pulls the lip to one side. 



Fig. 70. 

 Muscles of the head — left lateral view, a, Abducens ; h c d, Scuto-auriculaiis 

 externus, luferior, middle, aud superior i)ortions ; e, Levator palpebraj superioris 

 exteriius ; / /, Orbicularis palpebrarum ; </, Nasalis longus ; h, Depressor labii 

 inferioris; i, Buccinator; Ic, Masseter; I, Dilatator naris lateralis ; m, Dilatator 

 naris inferioris ; n, Dilatator naris superioris. 



DILATATOR NARIS LATERALIS. 



[Pyramklalis — S'u2)ermaxiHo-nasaIis Magnus.) 



{Pl. IL 7. EiG. 70. I.) 



This muscle is situated on the side of the cheek, between the 

 branches of the levator labii superioris, extending horizontally ; it 

 has a flat belly and tendon of origin. 



Attachments. — It arises from the anterior extremity of the 

 maxillary spine ; ii is inserted to the side of the nostril and the 

 upper lip, blending with the orbicularis oris. 



Action. — It dilates the nostril, acting on its external winij. 



