SUPERIOR MAXILLARY NERVE. f>47 



The supra-orbital branch passes forwards through the supra-orbital foramen, 

 and gives oftj in this situation, palpebral filaments to the upper eyelid. It then 

 ascends upon the forehead, and terminates in muscular, cutaneous, and pericranial 

 branches. The muscular branches supply the CJorrugator supercilii, Occipito- 

 frontalis, and Orbicularis palpebrarum, joining in the substance of the latter 

 muscle with the facial nerve. The cutaneous branches, two in number, an inner 

 and an outer, supply the integument of the cranium as far back as the occiput. 

 They are at first situated beneath the Occipito-frontalis, the inner branch per- 

 forating the frontal portion of the muscle, the outer branch its tendinous aponeu- 

 rosis. The pericranial branches are distributed to the pericranium over the 

 frontal and parietal bones. They are derived from the cutaneous branches whilst 

 beneath the muscle. 



The Nasal nerve is intermediate in size between the frontal and lachrymal, 

 and more deeply placed than the other branches of the ophthalmic. It enters the 

 orbit between the two heads of the External rectus, passes obliquely inwards 

 across the optic nerve beneath the Levator palpebra? and Superior rectus muscles, 

 to the inner wall of this cavity, where it enters the anterior ethmoidal foramen, 

 immediately below the Superior oblique. It then enters the cavity of the cranium, 

 traverses a shallow groove on the front of the cribriform plate of the ethmoid 

 bone, and passes down, through the slit by the side of the crista galli, into the 

 nose, where it divides into two branches, an internal and an external. The 

 internal branch supplies the mucous membrane near the fore part of the septum 

 of the nose. The external branch descends in a groove on the inner surface of 

 the nasal bone, and supplies a few filaments to the mucous membrane covering the 

 fore part of the outer wall of the nares as "far as the inferior spongy bone ; it 

 then leaves the cavity of the nose, between the lower border of the nasal bone and 

 the upper lateral cartilage of the nose, and, passing down beneath the Com- 

 pressor naris, supplies the integument of the ala and tip of the nose, joining with 

 the facial nerve. 



The branches of the nasal nerve are the ganglionic, ciliary, and infra- 

 trochlear. 



The ganglionic is a long, slender branch, about half an inch in length, which 

 usually arises from the nasal, between the two heads of the External rectus. It 

 passes forwards on the outer side of the optic nerve, and enters the superior and 

 posterior angle of the ciliary ganglion, forming its superior or long root. It is 

 sometimes joined by a filament from the cavernous plexus of the sympathetic, or 

 from the superior division of the third nerve. 



The long ciliary nerves, two or three in number, are given off from the nasal 

 as it crosses the optic nerve. They join the short ciliary nerves from the ciliary 

 ganglion, pierce the posterior part of the sclerotic, and, running forwards between 

 it and the choroid, are distributed to the Ciliary muscle and iris. 



The infra-trochlear branch is given off just as the nasal nerve passes through 

 the anterior ethmoidal foramen. It runs forwards along the upper border of the 

 Internal rectus, and is joined, beneath the pulley of the Superior oblique, by a 

 filament from the supra-trochlear nerve. It then passes to the inner angle of the 

 eye, and supplies the Orbicularis palpebrarum, the integument of the eyelids and 

 side of the nose, the conjunctiva, lachrymal sac, and caruncula lacrymalis. 





 (2.) SUPERIOR MAXILLARY NERVE (fig. 280). 



The SUPERIOR MAXILLARY, the second division of the fifth, is a sensory nerve. 

 It is intermediate, both in position and size, between the ophthalmic and inferior 

 maxillary. It commences at the middle of the Casserian ganglion as a flattened 

 plexiform band, and passes forwards through the foramen rotundum, where it be- 

 comes more cylindrical in form, and firmer in texture. It then crosses the spheno 

 maxillary fossa, traverses the infra-orbital canal in the floor of the orbit, and ap- 

 pears upon the face at the infra-orbital foramen. At its termination, the nerve 



