The vertebral artery is divided into four anatomic segments:
- V1 – Origin of the vessel to the foramina of the sixth cervical (C6) transverse process.
- V2 – Intraforaminal segment from the sixth to the second cervical vertebral body (C6 to C2).
- V3 – From the second cervical (C2) foramina to the base of the skull.
- V4 – Intracerebral segment of the vertebral artery. The vertebral arteries merge to form the basilar artery and are intradural.
