620 



CRANIAL NERVES. 



bicuspid teeth ; others are lost upon the lining membrane covering the fore part 

 of the inferior meatus. 



The palpebral brandies pass upwards beneath the Orbicularis Palpebrarum. 

 They supply this muscle, the integument, and conjunctiva of the lower eyelid 

 with sensation, joining at the outer angle of the orbit with the facial nerve and 

 malar branch of the orbital. 



The nasal branches pass inwards ; they supply the muscles and integument of 

 the side of the nose, and join with the nasal branch of the ophthalmic. 



The labial branches, the largest and most numerous, descend beneath the 

 Levator labii superioris, and are distributed to the integument and muscles of 

 the upper lip, the mucous membrane of the mouth, and labial glands. 



All these branches are joined, immediately beneath the orbit, by filaments 

 from the facial nerve, forming an intricate plexus, the infraorbital. 



SPHENO-PALATINE GANGLION. 



The Spheno-palatine Ganglion (Meckel's) (Fig. 345), the largest of the cranial 

 ganglia, is deeply placed in the spheno-maxillary fossa, close to the spheno- 

 palatine foramen. It is triangular, or heart-shaped in form, of a reddish-gray 

 color, and placed mainly behind the palatine branches of the superior maxillary 

 nerve, at the point where the sympathetic root joins the ganglion. It conse- 

 quently does not involve those nerves which pass to the palate and nose. Like 

 the other ganglia of the fifth nerve, it possesses a motor, a sensory, and a sym- 

 pathetic root. Its motor root is derived from the facial, through the Vidian ; 

 its sensory rootfrom the fifth ; and its sympathetic root from the carotid plexus, 

 through the Vidian. Its branches are divisible into four groups ; ascending, 

 which pass to the orbit ; descending, to the palate ; internal, to the nose ; and 

 posterior branches, to the pharynx. 



Fig. 345. The Spheno-palatine Ganglion and its Branches. 



The ascending branches are two or three delicate filaments, which enter the 

 orbit by the spheno-maxillary fissure, and supply the periosteum. Arnold 

 describes and delineates these branches as ascending to the optic nerve; one, to 

 the sixth nerve (Bock) ; and one, to the ophthalmic ganglion (Tiedemann). 



