The vertebral artery (Latin: arteria vertebralis) originates from the subclavian artery. It is a major vessel of the neck that provides arterial blood supply to the upper spinal cord, brainstem, cerebellum, and a part of the posterior cerebral hemisphere.
Each vertebral artery travels upwards, passing through the neck via the foramina transversaria of the upper six cervical vertebrae, reaching the cranial cavity via the foramen magnum. As they ascend along the medulla, both vertebral arteries run medially and unite at the level of the junction between the medulla and pons, forming the basilar artery in the midline. The basilar artery ascends superiorly in the basilar sulcus of the pons and divides into the right and left posterior cerebral arteries at the pontomesencephalic junction.
On its course, the vertebral artery gives off the following side branches:
- meningeal branches,
- anterior spinal artery,
- posterior spinal artery,
- spinal branches,
- muscular branches,
- posterior inferior cerebellar artery,
- medullary branches.
The meningeal branches of the vertebral artery arise near the foramen magnum and supply the posterior cranial fossa and the falx cerebelli.
Each anterior spinal artery arises from the vertebral artery in the cranial cavity, descends anterior to the medulla, and both unite to form a single trunk. This trunk descends along the ventral midline of the spinal cord and enters the vertebral canal via the intervertebral foramina to supply the spinal cord.
The posterior spinal artery originates from the vertebral artery near the medulla oblongata. It descends posteriorly embedded in the posterolateral sulcus of the spinal cord, and supplies the spinal cord.
The spinal branches of the vertebral artery arise in the neck, reach the spinal cord via the intervertebral foramina and supply it.
The muscular branches of the vertebral artery supply the deep muscles of the neck.
The posterior inferior cerebellar artery (PICA) arises from the vertebral artery near the lower end of the olive. The posterior inferior cerebellar artery supplies the medulla oblongata, the choroid plexus of the fourth ventricle, the dentate nucleus, the cerebellar hemisphere, and the inferior vermis.
The medullary branches of the vertebral artery supply the medulla oblongata.