Accurate 3d model of the blood vessels of the brain. The Circle of Willis (also called Willis' Circle, Loop of Willis, cerebral arterial circle, and Willis Polygon) is a circulatory anastomosis that supplies blood to the brain and surrounding structures. It is named after Thomas Willis (1621–1675), an English physician.
The Circle of Willis is a part of the cerebral circulation and is composed of the following arteries:
Anterior cerebral artery (left and right) Anterior communicating artery Internal carotid artery (left and right) Posterior cerebral artery (left and right) Posterior communicating artery (left and right) Basilar artery
The middle cerebral arteries, supplying the brain, are not considered part of the circle.