A contrast CT angiogram of the neck traces the vertebral artery from its origin on the subclavian artery upward. At which cervical vertebra does it normally enter the foramen transversarium?
- A C6 ✓
- B C5
- C C4
- D C7
Correct answer: A. C6
Explanation
The vertebral artery classically enters the foramen transversarium of the sixth cervical vertebra and ascends through the foramina of A6 to A1 before turning medially over the posterior arch of the atlas into the foramen magnum. The anterior tubercle of A6 is therefore called the carotid tubercle of Chassaignac, against which the artery can be compressed. Entry at A7 or A5 occurs as a variant but is not the standard description.
Reference: Gray's Anatomy for Students, 4th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.