Brain constitutes only 2% of the body weight but it requires 25% of oxygen, contents from each single breath. It is highly susceptible to lack of oxygen and blood supply; the blood supply to the brain is provided by pairs of two vessels, the internal carotid arteries and vertebral arteries. Both the arteries reach at the base of brain and form a circular arterial channel called the circulus arteriosus. Circle of Willis (CW) is a polygonal anastomotic channel at the base of the brain which unites the internal carotid and vertebrobasilar system of arteries in the interpeduncular fossa.
It maintains the steady and constant blood supply to the brain. The variations of circulus arteriosus are seen often. The aim of the present work is to find out the percentage of normal pattern of the CW and the frequency of variations of the CW and to study the morphological and morphometric aspects of all…
