Vertebral artery
Sub-branch · C6–C1 Foramen magnum Basilar
First and largest branch of each subclavian artery (drawn here from the left; identical on the right). Ascends through the foramina transversaria of C6 to C1, winds over the posterior arch of the atlas, passes through the foramen magnum and unites with its fellow at the pontomedullary junction to form the basilar artery. The pair supplies the posterior circulation: brainstem, cerebellum, occipital lobes and, via the anterior spinal artery, the cervical cord.
Traced from the start
- Arch of the aorta
- Left subclavian artery
- Vertebral artery
Detail
- Course
- Foramina transversaria C6–C1, foramen magnum, basilar artery
- Branches
- Anterior and posterior spinal arteries, posterior inferior cerebellar artery (PICA)
- Supplies
- Medulla and cerebellum directly; via the basilar the pons, midbrain, thalamus and occipital lobes
When it goes wrong
Vertebral artery dissection after neck manipulation or trauma
Neck pain then lateral medullary (Wallenberg) syndrome: ipsilateral facial pain and temperature loss, Horner's syndrome, ataxia, dysphagia; contralateral limb pain and temperature loss
Subclavian stenosis proximal to the vertebral origin
Retrograde vertebral flow during arm use steals from the basilar: vertigo, diplopia, drop attacks
Practise this structure
2 questions in the bank tagged Posterior Circulation.
A 63-year-old woman has three sudden episodes over two days of dizziness followed by double vision, slurred speech and veering to the left; each episode lasted…
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A 66-year-old man develops abrupt spinning vertigo and vomiting while gardening. Six hours later he remains unable to stand without support; examination shows h…
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