The basilar artery is a short blood vessel located at the base of the brain. Its numerous branches supply the pons, the cerebellum, and the posterior portion of the cerebrum, conveying about 45% of all the volume of oxygenated blood supplied to the human brain; the other 55% is brought up by the internal carotid artery.
The basilar artery is formed by the union of the right and left vertebral artery, which in turn arises from the first portion of the subclavian. From the point of origin, which is on the anterior-superior border of the medulla, it runs upwards and slightly forwards in a groove along the anterior surface of the pons. Having reached the superior border of pons, the basilar artery divides into the right and left posterior cerebral arteries, which are part of the circle of Willis that supply the brain.
Although it has a short course, the basilar artery gives off several important branches that supply the pons, cerebellum, and the occipital and temporal lobes of both cerebral hemispheres. These are: A) eight pontine arteries (four on each side); B) right and left anterior inferior cerebellar artery; C) right and left superior cerebellar artery, irrigating the cerebellum; D) right and left internal auditory artery (also called labyrinthine a.), which conveys oxygenated blood to the internal ear; and E) right and left posterior cerebral artery, which supplies the posterior part of cerebrum.
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| Above, inferior view of human brain, showing the vertebral and basilar artery. |
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| Schematic image showing basilar artery and its branches. |