886 



THE ORGANS OF SEN^E. 



FIG. 523. Bones and cartilages of septum of nose. 

 Right side. 



cent tissue and the corresponding parts of the opposite side, the tip 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 cartilagi- 

 nous plates (sesamoid cartilages), car- 

 tilagines minores. Above, it is con- 

 nected to the upper lateral cartilage 

 and front part of the cartilage of the 

 septum ; below, it is separated from 

 the margin of the nostril by dense 

 cellular tissue ; and in front, it forms, 

 with its fellow, the lobe of the nose. 



The cartilage of the septum is some- 

 what quadrilateral in form, thicker at 

 its margins than at its centre, and 

 completes the separation between the 

 nasal fossae in front. Its anterior mar- 

 gin, thickest above, is connected from 

 above downward with the nasal bones, the anterior margin 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, 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, the Levator labii superioris alaeque 

 nasi, the Dilatator naris, anterior and posterior, the Compressor nasi, the Com- 

 pressor narium minor, and the Depressor alae nasi. They have been described 

 above (page 399). 



The integument covering the dorsum and sides of the nose is thin, and loosely 

 connected with the subjacent parts, but where it forms the tip or lobe and the 

 alae of the nose it is thicker and more firmly adherent. It is furnished with a large 

 number of sebaceous follicles, the orifices of which are usually very distinct. 



The mucous membrane lining the interior of the nose is continuous with the 

 skin externally and with that which lines the nasal fossae within. 



The arteries of the nose are the lateralis nasi from the facial, and the inferior 

 artery of the septum from the superior coronary, which supply the alae and 

 septum, the sides and dorsum being supplied from the nasal branch of the 

 ophthalmic and the infra-orbital. 



The veins of the nose terminate in the facial and ophthalmic. 

 The nerves of the nose are branches from the facial, infra-orbital, and infra- 

 trochlear, and a filament from the nasal branch of the ophthalmic. 



Nasal Fossae. 



The nasal fossae are two irregular cavities situated in the middle of the face 

 and extending from before backward. They open in front by the two anterior 

 nares, and terminate in the pharynx, behind, by the posterior nares. The anterior 

 nares are somewhat pear-shaped apertures, each measuring about one inch vertically 

 and half an inch transversely at their widest part. The posterior nares are two 

 oval openings situated at the upper part of the anterior wall of the pharynx. 

 They are smaller in the body than in the skeleton, because narrowed by the 

 mucous membrane. Each opening measures an inch in the vertical and half an 

 inch in the transverse direction in a well-developed adult skull. 



