Variation in Blood Circulation of Brain-Circle of Willis

Human brain and its complex vascular network may be viewed as a �three pounds biological computer�. It is supplied by two internal carotid arteries, two vertebral arteries connected by a central anostomosis i. e. Circle of Willis in the interpeduncular fossa at the base of the brain. The circle of willis has been shown to exhibit many kinds of anatomical variations. The classical circle is bilaterally symmetrical and a complete ring of vessels. We have studied 20 cadavers during the routine dissection over the period of two years i. e. August 2015 to July 2017. In our study, out of 20 cadavers, we found one variation in branching pattern in circle of willis Here, the posterior communicating artery on the right side was very large while the posterior cerebral artery of the right side was very small.