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VII/1.4: Vessels of the base of the brain

The brain receives its blood supply from the base of the brain through the two internal carotid arteries (ICA) and the two vertebral arteries (VA) and their branches. In front of the border of the medulla oblongata and the pons the two VAs unite into basilar artery which runs in the basilar sulcus. The anterior spinal artery originates from the VAs, unites with the contralateral artery in front of the medulla oblongata, and continue its way on the ventral side of the spinal cord. The posterior inferior cerebellar artery originates at the posterolateral surface of the VAs. The two anterior inferior cerebellar arteries are branches of the basilar artery. The labyrinthine arteries that supply the inner ear, origate either from a loop-like curve of the anterior inferior cerebellar arteries (‘AICA’s loop’) or from the trunk of the basilar artery. The two superior cerebellar arteries are also branches of the basilar artery. The oculomotor nerves pass between these and the posterior cerebral arteries which constitute the end-branches of the basilar artery.

After a short pathway the two ICAs reach the base of the brain and divide into medial and anterior cerebral arteries. The two anterior cerebral arteries are linked by a short vessel in the longitudinal cerebral fissure called anterior communicating artery. The medial cerebral arteries divide into branches when they enter the lateral cerebral sulcus (Sylvian fissure). The ICA is connected with the posterior cerebral artery by the posterior communicating artery on both sides. This is how these vessels, the top of the basilar artery, the two anterior cerebral arteries, and the anterior communicating artery between them form the remarkable arterial anastomosis on the base of the brain called Circulus arteriosus cerebri, or Circle of Willis.

Other important branches include the anterior choroid artery; the thalamoperforating arteries which originate from the apex of the basilary artery and the posterior cerebral arteries and mostly enter through the posterior perforate substance; and the medial striate arteries which enter the anterior perforate substance.

Last modified: Thursday, 21 November 2013, 11:39 AM