Studies on the Cerebral Arteries of Macacus cyclopsis

A gross anatomical study on the distribution, course and branches of the cerebral arteries of 19 brains (38 cerebral hemispheres) from adult Macacus cyclopsis was done and compared with the reported results for man and other primates. The cerebral arterial system in Macacus cyclopsis is supplied by the A. carotis interna and A. vertebralis. The A. carotis interna separates into two terminal branches, the A. cerebri anterior and A. cerebri media. The A. cerebri anterior of each side unite to form the A. cerebri anterior communis. Prior to this union, the A. communicans anterior, which connects the A. cerebri anterior of each side, is seen in some cases. The A. vertebralis of each side unite to form the A. basilaris and its terminal branch becomes the A. cerebri posterior. Since the A. communicans posterior, which connects the A. carotis interna and A. cerebri posterior, is present, the so-called circulus arteriosus is formed at the base of the brain. This circulus arteriosus may be classified into two types; that in which the A. communicans anterior plays a role and that in which it does not. The most common type is that in which the A. communicans anterior does not play a role