Question

What is the Circle of Willis? What advantage does the Circle of Willis potentially confer upon those who have it?

Answer 1

The circle of Willis = Loop of Willis, or Cerebral arterial circle
It is a circulatory anastomosis that supplies blood to the brain.

It is a part of the cerebral circulation. It contains the below listed arteries.
1. Anterior communicating artery
2. Internal carotid artery (right and left)
3. Anterior cerebral artery (right and left)
4. Posterior communicating artery (right and left)
5. Posterior cerebral artery (right and left)

Function:
It allows for the collateral cerebral circulation i.e. when a vessel that supplies blood to the brain and surrounding tissues is blocked or narowed, the other blood vessels can compensate for their function to avoid the symptoms of ischemia.