Description
The cerebral arterial circle (circle of Willis, or circulus arteriosus cerebri) is a nine-sided circle-like loop of arteries. It is found along the base of the brain.
The nine sides of the cerebral arterial circle are formed by the following arteries:
- The one anterior side is formed by the full length of the anterior communicating artery- The two anterolateral sides are each formed by the proximal end of an anterior cerebral artery- The two lateral sides are each formed by the distal end of an internal carotid artery- The two posterolateral sides are each formed by the full length of a posterior communicating artery- The two posterior sides are each formed by the proximal end of a posterior cerebral artery
Overall, the arteries form the circle of Willis provide the majority of the arterial supply to the brain.