The<unk>  (dorsal<unk>  artery) arises from the vertebral artery, adjacent to the medulla oblongata. It passes posteriorly to descend the medulla passing in front of the posterior roots of the<unk>  nerves. Along its course it is reinforced by a succession of segmental or radicular branches, which enter the vertebral canal through the intervertebral foramina, forming a plexus called the vasocorona. The<unk> es continue as the two major trunks down to the lower part of the medulla<unk> is, and to the cauda equina.
Branches from the<unk> es form a free anastomosis around the posterior roots of the<unk>  nerves, and communicate, by means of very tortuous transverse branches, with the vessels of the opposite side.
Close to its origin each<unk>  gives off an ascending branch, which ends ipsilaterally near the fourth ventricle.
Posterior spinal artery
Anterior spinal artery
Vertebral artery
Basilar artery
Pontine arteries
Superior cerebellar artery
Posterior inferior cerebellar artery
Middle cerebral artery