The vertebrobasilar arterial system in guinea pig as compared with dog and human.

The arterial system formed by branches of the vertebral and basilar arteries in guinea pig was compared to that of dog and human. The vertebrobasilar arterial system in particular species shows similarities and differences, considering its structure and arising branches. The differences are mainly due to the length of the basilar artery. In guinea pig the vertebrobasilar system distribute blood to the 2/3 of the brain. The same distribution is in dog. In human the carotid system predominates in the supply of the brain.