278 THE MUSCLES. 



8. SUPERNASO-LABIALIS (LEVATOR LaBII SuPERIORIS Al^QUI NaSI) 



(Fig. 168, 15). 



Synonyms. — The maxillaris of Bourgelat. The levator labii superioris alxque nasi of Man. 

 (Levator labii superioris alxque nasi — Percivall. Fronto-lahialis — Leyh.) 



Situation — Direction — Form — Structure. — Situated on the side of the face, in 

 an obUque direction downwards and backwards, this is a wide muscle, flattened 

 on both sides, elongated from below to above, aponeurotic at its superior 

 extremity, and divided inf eriorly into two unequal branches, between which passes 

 the dilatator naris lateralis. 



Attachments.— It has its origin, by its superior aponeurosis, from the frontal 

 and nasal bones, and unites on the median line with the muscle of the opposite 

 side. Its anterior branch, the widest and thickest, goes to the external ala of the 

 nostril and to the upper lip, where its fibres are confounded with those of the 

 orbicularis. The posterior branch terminates at the commissure of the lips. 



Relations. — Outwards, with the skin ; inwards, with the levator labii superioris, 

 the posterior portion of the dilatator naris superioris, and vessels and nerves. Its 

 posterior branch covers the dilatator naris lateralis, and the anterior is covered 

 by that muscle. 



Actions. — It elevates the external ala of the nose, the upper lip, and the com- 

 missure of the lips. 



9. Great Supermaxillo-nasalis (Dilatator Naris Lateralis) (Fig. 168, 19). 



Synonyms. — The pyramidalis-nasi of Bourgelat. The caninus of Man. (Dilatator naris 

 lateralis — Percivall.) 



Situation — Direction — Form — Structure. — This muscle, situated on the side 

 of the face, between the two branches of the levator labii superioris, in an almost 

 vertical direction, is triangular in form, and slightly tendinous at its summit. 



Attachments. — It has its origin, by the aponeurotic fibres of its summit, from 

 the external face of the supermaxillary bone, below its ridge. It terminates, by 

 its base, on the skin covering the external wing of the nostril, its most posterior 

 fibres being confounded with those of the orbicularis of the hps. 



Relations. — Outwardly, with the skin and the inferior branch of the levator 

 labii superioris ; inwardly, with the anterior branch of that muscle, and with 

 vessels and nerves. 



Actions. — It dilates the external orifice of the nasal cavity, by pulling out- 

 wards the external wing of the nostril. 



10. Small Supermaxillo-nasalis (Dilatator Naris Superioris) 

 (Fig. 168, 25). 



Synonyms.—The nasalis brevis, and portion of the subcutaneous muscle of Bourgelat. 

 (Nasalis hrevis labii superioris — Percivall.) 



Girard has described, by the above name, a small, thick, and short muscular 

 fasciculus which covers the external process of the premaxillary bone, the fibres 

 of which, either originating from that, the supermaxillary bone, or the internal 

 face of the levator superioris muscle, terminate in the skin of the false nostril, 

 and the appendix of the inferior turbinated bone. 



Rigot has attached to this muscle that described by Bourgelat as the short 

 muscle. The latter is composed of short, transverse fibres, applied to the 



