BRANCHES OF THE INTERNAL MAXILLARY ARTERY. 677 



at tlie back of the roof of the nose (upper posterior nn*al branches). At 

 ts exit from the canal, the nerve receives a soft reddish offset (large 

 - /! /</<' from the sympathetic on the outer side of the 

 carotid artery. The continuation of the nerve enters the cranium 

 through the foramen lacerum, and is directed backwards in a groove 

 on the surface of the petrous part of the temporal bone, where it takes 

 the name of large superficial petrosal nerve (fag. 240, -, p. 678). Lastly 

 t is continued through the hiatus Fallopii, to join the geniculate 

 ganglion of the facial nerve (p. 679). 



The Vidian nerve is supposed to consist of motor and sympathetic vidian a 

 fibres in the same sheath, as in the connecting branches between the ^ l e ound 

 sympathetic and spinal ner\es. 



Directions. The students may now give their attention to the 

 emaining nerves in the nasal cavity. 



Dissection. The nasal nerve is to be sought behind the nasal Seek other 

 bone (fig. 239) by gently detaching the lining membrane, after ne 



aving cut off the projecting bone. A branch is given from the 

 nerve to the septum, but probably this, and the trunk of the 

 nerve, will be seen but imperfectly in the present condition of the 

 part. 



The terminal branches of the internal maxillary artery in the vessels of 

 ipheno-maxillaiy fossa have been laid bare in the dissection of no 

 Meckel's ganglion, but they may be now completely traced out. 



The NASAL NERVE (of the ophthalmic) (fig. 239, 6 ) has been already Nasal nerve 

 eeu in the skull and orbit. Entering the nasal fossa by an aperture ^^ ^ e . 

 at the fiont of the ethmoid bone, the nerve gives a branch to the gives 

 membrane of the septum, and then descends in a groove on the back 

 jf the nasal bone. At the lower margin of the latter it escapes 

 Between the bone and the upper lateral cartilage to the surface of 

 :he nose. 



BRANCHES. The branch to the septum (fig. 238) divides into branch to 

 filaments that ramify on the anterior part of that partition, and se 

 L'each nearly to the lower border. 



One or two filaments are likewise furnished by the nerve to the and to 

 mucous membrane on the outer wall of the nasal fossa : these extend 

 as low as the inferior spongy bone. 



TERMINAL BRANCHES OF THE INTERNAL MAXILLARY ARTERY. Branches of 

 The branches of the artery in the spheno-maxillary fossa, which ^SSary 

 jave not been examined, are the superior palatine, nasal, pterygo- artery are 

 palatine, and Vidian. 



The *<ii.riji' or d:wn<linij palatine is the largest branch, and 

 accompanies the large palatine nerve through the posterior palatine 

 :anal, and along the roof of the mouth ; it anastomoses behind the 

 incisor teeth with its fellow, and with the naso-palatine branch 

 through the incisor foramen. This artery supplies offsets to the 

 soft palate and tonsil through the other palatine canals, and some 

 twigs are furnished to the lining membrane of the nose. In the 

 roof of the mouth the mucous membrane, glands and gums receive 

 their vessels from it. 



