26 



APPLIED ANATOMY. 



arteries. These communicate across the median line through the anterior cerebral 

 and anterior communicating. Here again the anterior communicating branch is so 

 small that it is sometimes unable to furnish blood to the opposite side of the brain 



Optic nerve 



Ophthalmic artery 

 Third nerve 



Fourth nerve 



Ophthalmic branch 5th nerve 

 / Sixth nerve 

 ' / Internal carotid artery 



Maxillary branch 5th nerve 



Mandibular branch 5th 

 nerve 



Gasserian ganglion 

 turned forward 



Internal jugular 

 vein 



FIG. 30. The internal carotid artery in its course through the skull, showing its relations to the jugular vein and 

 cranial nerves. The Gasserian ganglion has been raised from its bed and turned forward. 



when the carotid supply of one side is shut off. This may cause syncope, stupor 

 or delirium, hemiplegia, and often softening and death. These results have not 



A. cerebri anterior 



A. cerebri media 



A. cerebri posterior 

 FIG. 31. Distribution of the A. cerebri anterior and A. cerebri posterior on the medial surface of the brain. 



infrequently followed ligation of the carotid artery in cases of aneurism. Obstruc- 

 tion of one vertebral artery would produce no effect because circulation would 

 be restored by the other vertebral through the basilar. 



