392 HEAD AND NECK 



The anterior angle of the septal cartilage is blunt and rounded, and does not 

 reach to the point of the nose, which is formed by the alar cartilages. 



The deviation of the septum nasi from the median plane will now (in all 

 probability) be seen to be due to a bulging to one side of the vomer and 

 perpendicular lamina of the ethmoid along their line of union. It is not 

 developed until after the seventh year. 



Dissection. The septal cartilage and thin bony part of the septum 

 must now be removed piecemeal. This must be done very carefully, as 

 it is necessary to preserve intact the muco-periosteum which clothes the 

 opposite side of the septum. It is in this muco-periosteum that the nerves 

 and blood vessels must be examined. 



Vessels and Nerves of the Septum Nasi. The following 

 is a list of the nerves : 



Nerves of Smell, . Olfactory. 



II. Naso-palatine. 

 2. Medial nasal branch of the anterior eth- 

 moidal nerve. 

 3. Nasal branches from spheno- palatine 

 ganglion and from the nerve of the 

 pterygoid canal (O.T. Vidian). 



The Medial Group of Olfactory Nerves. These nerves are 

 distributed in the muco-periosteum of the upper part of the nasal 

 septum and are barely distinguishable, except in a fresh part ; 

 further, they are so soft that it is hardly possible to isolate 

 them. They enter the nasal cavity through the medial series 

 of apertures in the cribriform plate of the ethmoid, and pro- 

 ceed downwards in grooves on the surface of the perpen- 

 dicular lamina of the same bone. 



Nervus Naso-palatinus. The naso-palatine nerve is a 

 long slender twig which can easily be detected upon the deep 

 surface of the muco-periosteum of the septum. It springs from 

 spheno-palatine ganglion, and enters the nasal cavity through 

 the spheno-palatine foramen. In the first part of its course 

 it runs medially upon the inferior surface of the body of the 

 sphenoid. Having gained the nasal septum, it changes its 

 direction and passes downwards and anteriorly, in a shallow 

 groove on the surface of the vomer under cover of the muco- 

 periosteum. Finally it enters the foramen of Scarpa, and, 

 where the two foramina of Scarpa open into the common 

 incisive foramen, the nerves of opposite sides unite in a plexus 

 from which branches are given to the mucous membrane 

 covering the anterior part of the hard palate. The naso- 

 palatine nerve is accompanied by the posterior nasal septal 

 artery ; and, as it lies on the surface of the vomer, it supplies 

 some small twigs to the muco-periosteum of the septum nasi. 



