Inferolateral Perspective of the Craniocervical Junction. The cerebellar tonsil is being retracted to demonstrate choroid plexus emanating from  the foramen of Luschka. The posterior inferior cerebellar artery can be observed coursing posteriorly to perfuse the dorsolateral medulla, cerebellar tonsils, and inferior portion of the posterior lobe.  Rootlets of the spinal accessory nerve can be seen coursing superiorly through the foramen magnum before joining the vagus and glossopharyngeal nerves to exit together through the jugular foramen. (Image courtesy of AL Rhoton, Jr.)