THE INTERNAL CAROTID ARTERY 



617 



recti, and Inferior oblique. This vessel gives off most of the anterior ciliary 

 arteries. Additional muscular branches a^e given off from the lacrimal and supra- 

 orbital arteries or from the ophthalmic itself. 



( For the Circulus or Circle of Willis, the posterior cerebral artery, and the blood- 

 vessels of the cerebellum, see page 619.) 



The anterior cerebral (a. praecerebralis, a. cerebri anterior) tfrises from the 

 internal carotid at the inner extremity of the sylvian fissure. It passes forward 

 and inward across the anterior perforated substance, above the optic nerve, to the 

 commencement of the intercerebral fissure. Here it comes into close relationship 

 with the anterior cerebral artery of the opposite side, and the two vessels are con- 

 nected by a short anastomosing trunk, about two lines, ^ inch (4 mm.), in length, 

 the anterior communicating artery. From this point the two vessels run side by 

 side in the intercerebral fissure, curve around the genu of the corpus callosum, 

 and, turning backward, continue along its upper surface to its posterior part, 

 where they terminate by anastomosing with the posterior cerebral arteries. 



FIG. 452. Vascular area of the inferior surface of the cerebrum. I. The part supplied by the anterior tem- 

 poral from the posterior cerebral artery. II. The part supplied by the posterior temporal from the posterior 

 cerebral artery. III. The part supplied by the occipital from the posterior cerebral artery. (After Duret.) 



Branches. In their course the anterior cerebral arteries give off the following 

 branches: 



Antero-median ganglionic. Anterior internal frontal. 



Inferior internal frontal. Middle internal frontal. 



Posterior internal frontal. 



The antero-median ganglionic are a group of small arteries which arise at the 

 commencement of the anterior cerebral artery; they pierce the anterior perforated 



