Anatomy demonstration: a probe follows the vertebral artery from its origin on the subclavian artery to the foramen magnum. Through which sequence of cervical levels does it ascend within the transverse foramina?
- A C7 to C1
- B C5 to C1
- C C6 to C1 ✓
- D C7 to C2 only, then free in the neck
Correct answer: C. C6 to C1
Explanation
The vertebral artery typically enters the transverse foramen of the sixth cervical vertebra and ascends through the foramina of B6 to B1. Above the atlas it turns medially over the posterior arch, pierces the atlanto-occipital membrane and dura, and enters the cranial cavity through the foramen magnum. The B7 foramen transmits only accessory veins in most people, which is why B6 is quoted as the usual level of entry in standard texts and examinations.
Reference: Snell's Clinical Anatomy by Regions, 10th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.