240 MUSCLES AND FASCIAE. 



scissors being passed upwards between the tendon and the conjunctiva, and the other between 

 the tendon and sclerotic. The student, when dissecting these muscles, should remove on one 

 side of the subject the conjunctiva from the front of the eye, in order to see more accurately 

 the position of these tendons, and on the opposite side the operation may be performed. 



5. NASAL REGION (fig. 148). 



Pyramidalis Nasi. 



Levator Labii Superioris Alaeque Nasi. 



Dilator Naris Posterior. 



Dilator Naris Anterior. 



Compressor Naris. 



Compressor Narium Minor. 



Depressor Alae Nasi. 



The Pyramidalis Nasi is a small pyramidal slip, prolonged downwards from 

 the Occipito-frontalis upon the side of the nose, where it becomes tendinous, and 

 blends with the Compressor naris. As the two muscles descend, they diverge, 

 leaving an angular interval between them. 



Relations. By its upper surface, with the skin. By its under surface, with the 

 frontal and nasal bones. 



The Levator Labii Superioris Alseque Nasi is a thin triangular muscle, placed 

 by the side of the nose, and extending between the inner margin of the orbit and 

 upper lip. It arises by a pointed extremity from the upper part of the nasal pro- 

 cess of the superior maxillary bone, and passing obliquely downwards and out- 

 wards, divides into two slips, one of which is inserted into the cartilage of the ala 

 of the nose, the other is prolonged into the upper lip, becoming blended with, 

 the Orbicularis and Levator labii proprius. 



Relations. In front, with the integument ; and with a small part of the Orbi- 

 cularis palpebrarum above. 



Lying upon the superior maxillary bone, beneath this muscle, is a longitudinal 

 muscular fasciculus about an inch in length. It is attached by one end near the 

 origin of the Compressor naris, and by the other to the nasal process about an 

 inch above it ; it was described by Albinus as the " Musculus anomalus," and by 

 Santorini, as the " Ehomboideus." 



The Dilator naris posterior is a small muscle, which is placed partly beneath 

 the proper elevator of the nose and lip. It arises from the margin of the nasal 

 notch of the superior maxilla, and from the sesamoid cartilages, and is inserted 

 into the skin near the margin of the nostril. 



The Dilator naris anterior is a thin, delicate fasciculus, passing from the carti- 

 lage of the ala of the nose to the integument near its margin. This muscle is 

 situated in front of the preceding. 



The Compressor Naris is a small, thin, triangular muscle, arising by its apex 

 from the superior maxillary bone, above and a little external to the incisive fossa ; 

 its fibres proceed upwards and inwards, expanding into a thin aponeurosis which 

 is attached to the fibro-cartilage of the nose, and is continuous on the bridge of 

 the nose with that of the muscle of the opposite side, and with the aponeurosis of 

 the Pyramidalis nasi. 



The Compressor Narium Minor is a small muscle, attached by one end to the 

 alar cartilage, and by the other to the integument at the end of the nose. 



The Depressor Alse Nasi is a short, radiated muscle, arising from the incisive 

 fossa of the superior maxilla ; its fibres ascend to be inserted into the septum, and 

 back part of the ala of the nose. This muscle lies between the mucous membrane 

 and muscular structure of the lip. 



Nerves. All the muscles of this group are supplied by the facial nerve. 



Actions. The Pyramidalis nasi draws down the inner angle of the eyebrow ; by 

 some anatomists it is also considered as an elevator of the ala, and, consequently, 

 a dilator of the nose. The Levator labii superioris alasque nasi draws upwards 





