Arterial supply of the spinal cord: 3 arteries: one anterior spinal artery and two posterior spinal arteries

– anatomic terminal arteries, with no collaterals

The anterior spinal artery: arises at the level of the foramen magnum by the junction of two branches, one from each vertebral artery

– provides 75% of the blood supply to the spinal cord

The posterior spinal arteries: arise from the posterior inferior cerebellar artery at the level of the foramen magnum

Along the way, they receive additional blood supply via:

– segmental arteries that arise from the aorta

– branches of the costocervical & intercostal arteries in thorax; lumbar and iliolumbar arteries in lumbar region; and lateral sacral arteries in pelvis – the largest branch is the great anterior radicular artery of Adamkiewicz (radicularis magna), which supplies the lower thoracic and upper lumbar parts of the cord and usually arises from a lower intercostal or a high lumbar artery

Spinal injury or aortic surgery or dissection may compromise the blood supply of the lower part of the spinal cord

Blood supply of anterior portion of cord is much more vulnerable than that of posterior portion and can be decompensated by occlusion of a large radicular branch or lesions of the aorta