#circle_of_Willis  a ring of arteries at the base of the brain
  supertype:  arteria__artery  a blood vessel that carries blood from the heart to the body
  part of:  encephalon__brain  that part of the central nervous system that includes all the higher nervous centers; enclosed within the skull; continuous with the spinal cord
     part of:  central_nervous_system__centralnervoussystem__CNS__systema_nervosum_centrale  the portion of the vertebrate nervous system consisting of the brain and spinal cord
        part of:  nervous_system__nervoussystem__systema_nervosum__systemanervosum  the sensory and control apparatus consisting of a network of nerve cells
           part of:  body__organic_structure__organicstructure__physical_structure  the entire physical structure of an organism (especially an animal or human being); "he felt as if his whole body were on fire"
     part of:  head__caput  the upper or front part of the body in animals; contains the face and brains; "he stuck his head out the window"
        part of:  animal__animate_being__animatebeing__beast__brute__creature__fauna  a living organism characterized by voluntary movement

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