Along its course, the basilar artery gives off five major branches. These are: anterior inferior cerebellar, internal auditory (labyrinthine), superior cerebellar, pontine and posteromedial arteries. The vessel terminates at a bifurcation where it gives off the paired posterior cerebral arteries that contribute to the circle of Willis.

The two vertebral arteries and the basilar artery are known as the vertebral basilar system, which supplies blood to the posterior part of the circle of Willis and joins with blood supplied to the anterior part of the circle of Willis from the internal carotid arteries.

The basilar artery runs cranially in the central groove of the pons towards the midbrain within the pontine cistern. It travels within this groove from the lower pontine border adjacent to the exit of the abducens nerve to the upper pontine border and the appearance of the oculomotor nerve .

The basilar is the main artery that carries blood to the back portion of your brain. It forms where the blood vessels that extend through your spinal cord (vertebral arteries) come together. The basilar artery and all its branches are called the vertebrobasilar system.