circle of Willis


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Noun1.circle of Willis - a ring of arteries at the base of the brain
arteria, arterial blood vessel, artery - a blood vessel that carries blood from the heart to the body
brain, encephalon - that part of the central nervous system that includes all the higher nervous centers; enclosed within the skull; continuous with the spinal cord
References in periodicals archive ?
In a study of 170 people from three groups - a control group with no headaches, those who had migraine with aura, and those who had migraine without aura - the team found that an incomplete circle of Willis was more common in people with migraine with aura (73 percent) and migraine without aura (67 percent), compared to a headache-free control group (51 percent).
For example, we're told that if an obstruction has developed over a period of years, the auxiliary circulation from the complex of arteries called the circle of Willis can take over providing blood to the impaired or vulnerable side of the brain.
By establishing an arterio-venous shunt, blood from collateral vessels via the Circle of Willis is redirected to the lower pressure venous return.