270 



JIUSCLES OF THE HEAD AXD NECK. 



subcutaneous, except at its origin, where the orbicularis palpebrarum 

 overlaps it a little. 



Pig. 203. Fig. 203. — Muscles of the side of the Xose and 



Upper Lip. § 



1, pyi-amidalis. nasi ; 2, levator labii siiperioris ala?que 

 nasi ; 3, compressor naris or triangularis ; 4, levator 

 proiirius aire nasi anterior ; 5, levator proprins aire nasi 

 ]iosterior or dilatator : G, depressor alae nasi ; 7, orbicu- 

 laris oris ; 7*, naso-labialis. 



The depressor alae nasi is a small flat 

 muscle which arises Itoui tlie superior incisor 

 fossa, and is inserted into the septum and 

 posterior part of the ala of the nose. "The 

 external fibres curve forwards and downwards 

 to the ala. 



Besides the muscles above described there 

 are other irregular and often indistinct fibres 

 which cover the small alar cartilages of the 

 nose. Of these the following may be dis- 

 tinguished. 



The levator proprins alee nasi posterior, or dilatator naris pos- 

 terior, is attached to the margin of the ascending process of the 

 superior maxillary bone and the smaller (sesamoid) cartilages of the 

 ala nasi on the one hand, and to the skin on the other. Another set of 

 fibres, the levator proprius alae nasi anterior, or dilatator naris 

 anterior, is interposed between the cartilage of the aperture of the nose 

 and skin, to both of which it is attached. The musculus anomalus of 

 Albinus is a longitudinal muscular slip of more than an inch in length, 

 lying beneath the common elevator of the lip and ala of the nose, con- 

 nected by the lower end with the origin of the compressor naris, and 

 attached exclusively to the superior maxillary ];)one. 



Varirtics. — The compressor naris is sometimes very slightly developed, or even 

 reduced to an aponeurotic condition. The dilators and depressor of the nostril are 

 also subject to considerable variations in strength and in the mode of their 

 attachment. 



Actions. — Tlie pyi-amidalis nasi muscle, being- continuous with the frontalis, 

 is the means of giving that muscle a more fixed attachment to the dorsum of the 

 nose, and assists in di-awing down the integument of the forehead, and in pro- 

 ducing wrinkles across the root of the nose ; it probably acts also as an opponent 

 to the compressor naris muscle. The compressor naris, acting along with its 

 fellow of the other side, depresses the cartilaginous ^jart of the nose, and to some 

 extent also compresses the ala3 together. The actions of the other muscles are 

 sufficiently indicated by their names ; the dilatation of the ala) is perceptible in 

 natui'al inspiration, and is well marked in dyspnoea. 



MUSCLES OF THE LIPS AND MOUTH. 



Around the orifice of the mouth are situated an orbicular muscle 

 with concentric fibres, and numerous other muscles, whose fibres con- 

 verge towards the aperture, viz., superiorly the common elevator of the 

 lip and nose already described, the proper elevator of the upper lip, the 

 elevator of the angle of the mouth and the zygomatic muscles, laterally 

 the risorius and buccinator muscles, and, inferioriy, the depressor of 



