THE FIFTH NERVE 341 



roots, viz., the long or sensor, from the nasal branch of the 

 ophthalmic; a short or motor, from the branch of the third 

 to the inferior oblique; and the sympathetic root, from the 

 cavernous plexus. 



Branches. Six or eight short ciliary, which run with the 

 ciliary arteries above and below the optic nerve, and are joined 

 by a branch from the long ciliary of the nasal. They pierce 

 the sclerotic to supply the ciliary muscle and iris. 



The second division of the fifth nerve (superior maxillary) is 

 sensor and enters the foramen rotundum, crosses the spheno- 

 maxillary fossa, and, as the infraorbital, traverses the canal, 

 emerges from the foramen to end on the face in palpcbral, 

 nasal, and labial branches the first set, to lower lid; the second, 

 to side of nose; and the third, to upper lip. These branches 

 join with the facial to form the infraorbital plexus. The superior 

 maxillary nerve also gives off two branches to Mcckel's ganglion, 

 an orbital and alveolar branch, and a recurrent branch to the 

 dura mater. 



The orbital or temporomalar branch enters the orbit by the 

 sphenomaxillary fissure, and divides into two branches, which 

 pierce the malar bone. The malar branch supplies the skin 

 of the cheek, and joins the facial. The temporal branch, after 

 piercing the malar bone, enters the temporal fossa, and ends 

 in the skin over the forepart of the temporal region, joining 

 the facial and auriculotemporal nerves. 



The alveolar or superior dental nerves are three: The pos- 

 terior divides into two, which run on the zygomatic surface 

 of the superior maxilla, supplying the gum and the mucous 

 membrane of the cheek, and enter the posterior dental canals 

 to the molar teeth. The middle runs to the bicuspids along 

 a canal in the antrum. The anterior descends in its canal, 

 and gives a nasal branch to the pituitary membrane, and 

 dental branches to the canine and incisor teeth. 



Meckel's ganglion is also called the sphenopalatine, and 

 lies in the sphenomaxillary fossa, close to the sphenopalatine 

 foramen and below the superior maxillary nerve. Its motor 

 root comes from the facial through the large superficial petrosal 

 from the geniculate ganglion (see Vidian Nerve), its sensor root 

 from the two ganglionic branches of the superior maxillary 

 nerve, and the sympathetic root from the carotid plexus through 

 the large deep petrosal. Its branches are as follows: 



