720 



DISSECTION OF THE BRAIN. 



transverse a. The transverse arteries of the pons are four or five small twigs, 

 to the pons ; W j 1 j c j 1 are na med from their direction, and are distributed to the 



substance of the pons. One of them ( 9 ) gives an offset (auditory) 



to the internal ear along the auditory nerve. 



b. Like the branches of this set is the anterior inferior cerebellar 

 artery : it arises from the basilar trunk, and is distributed to the 

 fore part of the under surface of the cerebellar hemisphere. 



c. The superior cerebellar artery ( 8 ) is a considerable vessel derived 

 from the basilar so near the termination as to be often described as 

 one of the final branches of that vessel. Its destination is the upper 

 surface of the cerebellum, to which it is directed backwards, winding 

 round the crus cerebri below the third, but parallel to the fourth 



auditory ; 



anterior 

 cerebellar, 



Superior 

 cerebellar. 



Prsecuneal. 



Artery of corpus callosum. 



Parieto-occipital. 



Internal frontal. 



Central. 



ANTERIOR CERKBRAL. 



Internal orbital. 



Posterior communicating. 



Anterior choroid. 

 POSTERIOR CEREBRAL. 



Posterior choroid. 



\ Temporal. 

 Temporal. 



giving 

 offsets 

 to velum. 



Posterior 



cerebral 



artery 



branches of 

 which are 

 cortical, 



central, 



FIG. 258. THE MESIAL AND UNDER SURFACES OP THE CEREBRAL HEMI- 

 SPHERE, SHOWING THE DISTRIBUTION OF THE ANTERIOR AND POSTERIOR 



CEREBRAL ARTERIES. 



nerve. The ramifications of the artery spread over the upper surface 

 of the cerebellum, and anastomose with the vessel of the opposite 

 side, and with the inferior cerebellar arteries. 



Some twigs of this vessel enter the fold of the pia mater (velum 

 interpositum) which projects into the cerebrum. 



d. The POSTERIOR CEREBRAL ARTERY (fig. 257, 7 , and fig. 258) takes a 

 backward course, similar to that of the preceding artery, but separated 

 from it by the third nerve. It winds round the crus cerebri and is 

 directed upwards and backwards to beneath the posterior end of the 

 corpus callosum ; it enters the calcarine fissure and divides into its 

 two terminal branches, parieto-occipital and calcarine. Near its 

 origin it is joined by the posterior communicating artery, passing 

 backwards on each side from the terminal part of the internal carotid. 

 The artery gives off numerous branches 



1. The deep or central arteries leave the trunk close to its origin, 



