678 



ORGANS OF SENSE. 



Fig. 366. Bones and Cartilages of Septum 

 of Nose. Bight Side. 



which varies considerably in different individuals. The dorsum terminates 

 below in a rounded eminence, the lobe of the nose. 



The nose is composed of a framework of bones and cartilages, the latter 

 being slightly acted upon by certain muscles. It is covered externally by the 

 integument, internally by mucous membrane, and supplied with vessels and 

 nerves. 



The bony framework occupies the upper part of the organ; it consists of the 

 nasal bones, and the nasal processes of the superior maxillary. 



The cartilaginous framework consists of five pieces, the two upper, and the two 

 lower lateral cartilages, and the cartilage of the septum. 



The upper lateral cartilages are situated below the free margin of the nasal 

 bones ; each cartilage is flattened, and triangular in shape. Its anterior margin 

 is thicker than the posterior, and connected with the fibro-cartilage of the sep- 

 tum. Its posterior margin is attached to the nasal process of the superior max- 

 illary and nasal bones. Its inferior margin is connected by fibrous tissue with 

 the lower lateral cartilage; one surface is turned outwards, the other inwards 

 towards the nasal cavity. 



The lower lateral cartilages are two thin, flexible plates, situated immediately 

 below the preceding, and curved in such a manner as to form the inner and outer 



walls of each orifice of the nostril. 

 The portion which forms the inner 

 wall, thicker than the rest, is loosely 

 connected with the same part of the 

 opposite cartilage, and forms a small 

 part of the columna. Its outer ex- 

 tremity, free, rounded, and projecting, 

 forms, with the thickened integument 

 and subjacent tissue, the lobe of the 

 nose. The part which forms the 

 outer wall is curved to correspond 

 with the ala of the nose ; it is oval 

 and flattened, narrow behind, where 

 it is connected with the nasal process 

 of the superior maxilla by a tough 

 fibrous membrane, in which are found 

 three or four small cartilaginous 

 plates (sesamoid cartilages), cartila- 

 gines minores. Above, it is connected 

 to the upper lateral cartilage and 

 front part of the cartilage of the septum ; below, it is separated from the mar- 

 gin of the nostril by dense cellular tissue ; and in front, it forms, with its fellow, 

 the prominence of the tip of the nose. 



The cartilage of the septum is somewhat triangular in form, thicker at its 

 margins than at its centre, and completes the separation between the nasal fossa 

 in front. Its anterior margin, thickest above, is connected from above down- 

 wards with the nasal bones, the front part of the two upper lateral cartilages, 

 and the inner portion of the two lower lateral cartilages. Its posterior margin 

 is connected with the perpendicular lamella of the ethmoid; its inferior margin 

 with the vomer and the palate processes of the superior maxillary bones. 



These various cartilages are connected to each other, and to the bones, by a 

 tough fibrous membrane, the perichondrium, which allows the utmost facility 

 of movement between them. 



The muscles of the nose are situated immediately beneath the integument ; 

 they are (on each side) the Pyramidalis Nasi, theLevator Labii Superioris Ala-- 

 que Nasi, the Dilatator Naris (anterior and posterior,) the Compressor Nasi, the 

 Compressor Narium Minor, and the Depressor Ahu Nasi. They have been 

 already described under the muscles of the nasal region. 



