Vessel
Vertebral artery
Cervical arterial passage into the posterior cranial circulation
High-yield
The usual entry is the C6 transverse foramen, followed by ascent to C1 and a turn toward foramen magnum. Higher or lower entry, different origins and unequal vessel size are recognized variants.
Overview
The vertebral artery usually arises from the subclavian and ascends through cervical transverse foramina. Above the atlas it turns across the posterior arch before entering through foramen magnum. Intracranial branches supply medullary and spinal regions, and the paired vertebral arteries usually unite to form the basilar trunk.
Reference facts
- Origin
- Usually the first part of the subclavian artery; a direct aortic origin, especially on the left, is one recognized variant.
- Course
- Usually enters the transverse foramina at C6, ascends to C1, curves over the atlas posterior arch and crosses dura to enter the cranium through foramen magnum.
- Branches
- Muscular and spinal branches in the neck; intracranial medullary/meningeal branches, anterior spinal contributions and usually PICA. Posterior spinal supply may arise directly or through PICA.
- Supplies
- Cervical spinal and neighboring neck structures, medulla and parts of cerebellum; basilar continuation distributes flow to more rostral posterior territories.
Clinical correlation
Vertebral dissection may follow trauma or occur without a major mechanical trigger. Local narrowing and emboli can compromise posterior circulation, producing varied brainstem or cerebellar deficits, including lateral medullary syndrome in some cases.
Frequently asked questions
Where does the vertebral artery originate?
Usually the first part of the subclavian artery; a direct aortic origin, especially on the left, is one recognized variant.
What does the vertebral artery supply?
Cervical spinal and neighboring neck structures, medulla and parts of cerebellum; basilar continuation distributes flow to more rostral posterior territories.
What are the branches of the vertebral artery?
Muscular and spinal branches in the neck; intracranial medullary/meningeal branches, anterior spinal contributions and usually PICA. Posterior spinal supply may arise directly or through PICA.
What is the course of the vertebral artery?
Usually enters the transverse foramina at C6, ascends to C1, curves over the atlas posterior arch and crosses dura to enter the cranium through foramen magnum.