THE PERIPHERAL NERi^OUS SYSTEM. 37 ^ 



pulley to near the middle of the supraorbital crest of the frontal 

 bone. Here it passes out of the orbit and is distributed to the 

 integument of the upper eyelid and the adjacent region at the 

 side of the nose. 



b. N. infratrochlearis. — The infratrochlear nerve passes 

 between the superior rectus and the superior oblique in the first 

 part of its course. It then passes ventrad of the superior 

 oblique and ventrad of the pulley to be distributed to the in- 

 tegument of the upper eyelid near the inner angle. 



c. N. ethmoidalis. — The ethmoidal nerve passes along 

 with the ethmoidal artery through the ethmoidal foramen (or 

 foramina) in the orbital plate of the frontal bone. It is finally 

 distributed to the mucosa of the nose and to the cartilage and 

 integument of the snout. 



d. N. ciliaris longus. — The long ciliary nerve arises from 

 the ophthalmic and passes along the optic nerve to be dis- 

 tributed to the eyeball. It divides into several branches before 

 penetrating the sclerotic. 



One or two small communicating branches to the ciliary 

 ganglion are given off at about the same point as the long 

 ciliary nerve. (For a description of this ganglion see the 

 account of the oculomotor nerve, page 369.) 



2. N. maxillaris. — The maxillary nerve, the second divi- 

 sion of N. trigeminus, rises from the semilunar (Gasserian) 

 ganglion and leaves the skull by the foramen rotundum. It 

 is the sensory nerve of the palate, upper teeth and upper lip, 

 and of part of the forehead and cheek. 



On leaving the foramen the maxillary nerve divides into 

 three branches, the two infraorbital nerves (Fig. 154,/) and 

 the sphenopalatine (Fig. i 54, g). Two smaller branches are 

 likewise given off either within or just outside of the foramen, 

 the lachrymal nerve (Fig. 154,7') and the zygomatic (sub- 

 cutaneus mal^e) (Fig. i 54, i). 



a. N. lachrymalis (Fig. 154, J; Fig. 155, in). — The 

 lachrymal nerve passes along the periorbita to the lachrymal 

 gland (Fig, 154, 11), to which it gives branches. It then con- 

 tinues caudad of the zygomatic process of the temporal to the 

 integument; here it turns caudad and is distributed to the integ- 



