752- 



HUMAN ANATOMY. 



opening directly into the posterior cerebral artery. In its course it gives off twigs 

 to the tuber cinereum, the corpora albicantia, and the crus cerebri. 



5. The Anterior Choroid Artery. — The anterior choroid artery (a. choroi- 

 dea) (Fig. 702) arises from the posterior surface of the internal carotid, slightly 

 distal to the posterior communicating artery. It is directed outward and backward 

 at first, and then, curving upward between the brain-stem and the temporal lobe, it 

 gives branches to the hippocampus major. It is then continued upward and for- 

 ward as the artery of the choroid plexus of the lateral ventricle, and anastomoses at 

 the foramen of Monro with the artery of the choroid plexus of the third ventricle, 

 which comes from the superior cerebellar branch of the basilar artery. 



6. The Middle Cerebral Artery. — The middle cerebral artery (a. cerebri 

 media) (Figs. 699, 702) is one of the terminal branches of the internal carotid. It 

 passes at first outward to the lower end of the Sylvian fissure, and is then directed 

 backward and upward, lying at first deeply in the fissure close to the surface of the 



Fig. 700. 



Middle internal frontal artery 



Posterior internal 

 tr( 'ntal artery 



Corpus 

 caliosum 



Fornix 



Anterior in- 

 ternal frontal 

 artery 

 Middle 

 commissure 

 Internal 

 orbital artery 

 Anterior 

 cerebral artery 



Anterior commun- 

 icating artery 



Internal carotid artery 



External orbital artery' 



Middle cerebral artery 

 From temporal branch of middle cerebral 



Posterior communicating artery Anterior choroid 



artery 



Parieto-occip- 

 ital artery 



\'elum 

 interpositum 



Posterior 

 choroid arterj 



Temporal branches of 

 posterior cerebral 



Posterior cerebral artery 



Mesial surface of cerebral hemisphere, showing cortical branches of anterior 

 and posterior cerebral arteries. 



island of Reil, but gradually becoming more superficial until at the posterior ex- 

 tremity of the horizontal limb of the fissure it reaches the surface and divides into 

 branches which ramify over the lateral surface of the cerebral hemisphere. 



Branches. — In its course outward to enter the Sylvian fissure it gives off a number of small 

 central branches which penetrate the substance of the cerebral hemisphere at the anterior per- 

 forated space, and, as the striate arteries, supply the corpus striatum. These antero-lateral 

 ganglionic branches, as they are often called, are arranged as two groups: (a) the internal 

 striate arteries, which pass upward through the lenticular nucleus (globus pallidus) and the 

 internal capsule and end in the caudate nucleus, supplying the anterior part of the structures 

 traversed ; {b) the external striate arteries, which after traversing the putamen and the internal 

 capsule terminate in either the caudate nucleus or the optic thalamus. One of the former 

 (lenticulo-striate) vessels, which passes around the outer border of the lenticular nucleus before 

 traversing its substance, is larger than the others and, since it frequently ruptures, is known as 

 the artery of cerebral hemorrhage. While in the Sylvian fissure the middle cerebral artery 

 gives of? numerous branches to the cortex of the island of Reil and continues into the cortical 

 bi-anches, which are distributed to the lateral surface of the hemisphere and are usually four in 



