Vertebral aa.

The vertebral aa. are branches of the subclavian a. that pass posteriorly to enter the transverse foramina of the cervical vertebrae.  They enter the skull through the foramen magnum and provide the posterior circulation of the brain:

• PICA (posterior inferior cerebellar artery)

• Basilar a.

• AICA (anterior inferior cerebellar artery)

• Superior cerebellar a.

• Posterior cerebral a.