The basilar artery (Latin: arteria basilaris) is a large blood vessel that is formed by the union of the two vertebral arteries.
The basilar artery arises at the mid-medullary level, ascends vertically in a shallow medial groove on the ventral pontine surface, reaches the interpeduncular cistern and divides into two posterior cerebral arteries (terminal branches of the basilar artery).
The basilar artery gives off several side branches, including:
The pontine branches of the basilar artery are small branches that originate from the front and sides of the basilar artery as it travels along the pons.
The labyrinthine artery (also internal auditory artery) is a branch that sometimes arises from the lower part of the basilar artery.
The anterior inferior cerebellar artery (AICA) originates from the inferior part of the basilar artery and supplies the inferior cerebellar surface.
The superior cerebellar artery arises from the superior part of the basilar artery and supplies the superior cerebellar surface, pineal body, superior medullary velum, and tela choroidea of the third ventricle.
Thus, regions supplied by the basilar artery include the pons, the inferior cerebellar surface, inner ear, upper medulla oblongata, superior cerebellar surface, pineal body, superior medullary velum, and tela choroidea of the third ventricle.