282 THE NERVOUS SYSTEM 



1. The Ophthalmic Branch passes forward along the outer 

 wall of the cavernous sinus, divides into three branches 

 (a) lachrymal, (b) frontal, (c) nasal and enters the orbit 

 by the sphenoidal fissure. It communicates with the cavern- 

 ous sympathetic, third and sixth nerves, (a) The lachrymal 

 branch, running along the outer wall of the orbit, reaches 

 the lachrymal gland, gives off filaments to it and to the con- 

 junctiva, and pierces the tarsal ligament to be finally dis- 

 tributed to the integument of the upper lid. (b) The 

 frontal branch runs along the upper wall of the orbit and 

 separates into the supra-trochlear and supra-orbital 

 branches. The former of these leaves the orbit in front and 

 turns up over the bone to supply the integument of the 

 lower forehead ; the latter traverses the supra-orbital canal, 

 escapes by. the foramen of the same name, and supplies 

 the skin as far back as the occiput as well as the peri- 

 cranium in the frontal and parietal regions, (c) The nasal 

 branch, crossing to the inner wall of the orbit, enters the 

 anterior ethmoidal foramen, passes thus into the cranium 

 again, runs in a groove on the cribriform plate of the eth- 

 moid and finds exit into the nose through a slit by the side 

 of the crista galli. Here it gives off branches which supply 

 common sensation to the mucous membrane of the fore part 

 of the nose, and then running in a groove on the posterior 

 surface of the nasal bone, it leaves the cavity at the lower 

 border of that bone to supply the integument of the ala and 

 tip of the nose. From the nasal nerve pass fibers to the oph- 

 thalmic ganglion and to the ciliary muscle, iris and cornea. 



2. The Superior Maxillary Branch passes away from the 

 Gasserian ganglion and leaves the cranium by the foramen 

 rotundum. Crossing the spheno-maxillary fossa it enters 

 the orbit through the spheno-maxillary fissure and traverses 

 the infra-orbital canal to emerge upon the face at the infra- 

 orbital foramen. In the cranium it gives off a meningeal 

 branch to supply the neighboring dura mater. In the 

 spheno-maxillary fossa it supplies branches (a) to the 



