174 MUSCLES OF THE HEAD AND NECK. 



The pyramidalis nasi, continuous with the innermost fibres of the fron- 

 talis muscle, extends downwards from the root of the nose, over the 

 upper part of it, and terminates by a tendinous expansion in connection 

 with the compressor naris muscle. The muscles of opposite sides, united 

 superiorly, diverge slightly as they descend. 



The compressor naris, a thin triangular muscle, arises narrow and fleshy 

 from the canine fossa in the superior maxillary bone, and proceeding inwards, 

 gradually expands into a thin aponeurosis, which is partly blended with that 

 of the corresponding muscle of the opposite side, and with the pyramidalis 

 nasi, and is partly attached to the cartilage of the nose. It is concealed at 

 its origin by the proper elevator of the lip, and is crossed by the common 

 elevator. 



Fig. 155. pig 155 MUSCLES OP THE SIDE OF THE NOSE AND 



UPPER LIP. 



1, pyramidalis nasi ; 2, levator labii superioris aljeque 

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

 proprius alee nasi anterior ; 5, levator proprius alse nasi 

 posterior or dilatator ; 6, depressor alee nasi ; 7, orbicu- 

 laris oris ; 7*, naso-labialis. 



The levator labii superioris alceque nasi, the 

 common elevator of the lip and nose, lies along 

 the side of the nose, extending from the inner 

 margin of the orbit to the upper lip. It arises 

 by a pointed process from the upper extremity 

 of the nasal process of the superior maxillary 

 bone, and, as it descends, separates into two 

 fasciculi ; one of these, much smaller than the 

 other, becomes attached to the wing of the nose, 

 whilst the other is prolonged to the upper lip, 

 where it is blended with the orbicularis and the 



special elevator muscle. It is subcutaneous, except at its origin, where the 



orbicularis palpebrarum overlaps it a little. 



Anomalous Fibres. Beneath the common elevator of the lip and ala of the nose, 

 and connected by the lower end with the origin of the compressor naris, will be found 

 a longitudinal muscular slip, more than an inch in length, attached exclusively to the 

 superior maxillary bone. It was named " rhomboideus " by Santorini and (in con- 

 sequence of being attached only to one bone, and producing therefore no motion) 

 " anomalus " by Albinus. 



The depressor alee nasi is a small flat muscle which arises from the 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 distinguished. 



The levator proprius alee nasi posterior, or dilatator naris posterior, 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 alee 

 nasi anterior, or dilatator naris anterior, is interposed between the cartilage 

 of the aperture of the nose and the skin, to both of which it is attached. 



ACTIONS. The pyramidalis muscle, being continuous with the occipito-frontalis, is 

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



