126 



Cranial Nerves. 



m. N. 



OCULOMOT. re N. 

 NASOrCILIAR.J TRgCHLEAR. 



.VI. N. 

 ABDUC. 



M. rect. ext. &ANBL . CILIARE 

 NN. CILIARES 



470. The Oculomotor, Troclilear and Abducent 



Nerve 8= View from the outside. 



The sixth nerve, the abducent, Nervus abducens, makes its appearance 

 at the posterior border of the Pos Varolii, passes forwards through 

 the cavernous sinus, in which it lies on the outer side of the internal 

 carotid artery (Carotis cerebralis), and is joined by several filaments from 

 the sympathetic. It then enters the orbit through the sphenoidal fissure 

 and passes between the two heads of the J\L rectus cxtcrnus, to be distri- 

 buted to the muscle, which it pierces on its ocular surface. 



The fifth, trifacial or t r i g e m i n a 1 n e r v e, Ncrvns trigeminus, 

 the largest of the cranial nerves, arises by two separate roots. The larger, 

 sensory, posterior root makes its appearance at the anterior surface 

 of the Cm* cerebelli ad pontem ; the much smaller, motor, anterior root, 

 between the anterior transverse fibres of the Pon$ YaroliL The two roots 

 of the nerve pass forwards through an oval opening in the dura mater, 

 Caviu/i Me.ckdii, at the superior surface of the petrous portion of the 

 temporal bone, where the fibres of the sensory root form a large s e m i- 

 1 u 11 a r g a n g 1 i o n, the Ganglion Gawri s. wmilunarv. From the convex border 

 of this ganglion the three large branches of the trifacial nerve pro- 

 ceed: the I. ophthalmic branch, Ramus oplifhalmtcus, the II. supe- 

 rior maxillary b r a n c h, Ham-u* supramaxittaris, and the III. inferior 

 maxillary, RCUIIHH inframaxittaris. 



