The circle of Willis is a junction of several important arteries at the bottom part of the brain. Learn more about its anatomy, function, and more.

The image depicts the anatomy of the circle of Willis (A) and representative subjects with a complete (B) and incomplete circle of Willis (C).

The driver of the car that hit a CTA bus, which then crashed into a bank at the base of Willis Tower early Saturday morning, has been cited, police said. Around 1:55 a.m., the car, which was southb… ...