Arteries of brain Two sources Internal carotid artery: supplies anterior 2 /3 of cerebral hemisphere and parts of diencephalon vertebral artery supplies posterior 1/3 of cerebral hemisphere and parts of diencephalon, brain stem and cerebellumArteries of brain Two sources ◼ Internal carotid artery: supplies anterior 2/3 of cerebral hemisphere and parts of diencephalon ◼ Vertebral artery: supplies postterior 1/3 of cerebral hemisphere and parts of diencephalon, brain stem and cerebellum