414 



THE ARTERIES OF THE HEAD AND NECK. 



parietal supplies the ascending parietal convolution and the fore part of the superior 

 parietal lobule ; and (d) the parieto-temporal, much the largest and often double, 

 runs backwards in the posterior limb of the fissure of Sylvius, and ramifies upwards 



Fig. 347. THE ARTERIES OF THE BASE OF THE CEREBRUM (after Merkel, and from nature). 



(GK D. T.) 



On the left side the greater part of the temporal lobe and the lower part of the occipital lobe are 

 taken away, so as to open the inferior and posterior cornua of the lateral ventricle ; the midbrain is 

 divided close above the pons, and the posterior cerebral arteries are cut at their origin from the 

 basilar. 



Central arteries : am, antero-mesial group, arising from the anterior cerebral ; al, antero-lateral 

 group, from the middle cerebral ; pm, and pi (on the optic thalamus), postero-mesial and postero- 

 lateral groups, from the posterior cerebral. Choroid arteries: a ch, anterior, from the internal 

 carotid ; p ch (on the splenium of the corpus callosum), posterior, from the posterior cerebral. 

 Cortical arteries : 1,1, inferior internal frontal, from the anterior cerebral ; 2, inferior external frontal, 

 3, ascending frontal, 4, ascending parietal, and 5, parieto-temporal, from the middle cerebral ; 6, an- 

 terior temporal, 7, posterior temporal, and 8, occipital, from the posterior cerebral. 



