Blood supply of the spinal cord
Arterial supply : Supplied by 3 small arteries + feeder arteries
Segmental spinal arteries
ASA and PSA arteries are reinforced by segmental arteries, which enter the vertebral canal through the inter vertebral foramina. These arteries are branches of arteries outside the vertebral column (deep cervical, intercostal and lumbar arteries). Segmental arteries give rise to anterior and posterior radicular arteries.
Enter the vertebral arteries and anastomose with the ASA & PSA. The most important feeder artery is the Great anterior medullar artery (GAM) of Adamkiewicz. It arises from the aorta at lower thoracic or upper lumbar vertebral levels. This artery is unilateral. It lies in the left side of most people. It represents the major source of blood to the lower 2/3 of the spinal cord.
Veins of the spinal cord
Drain mainly into the veins of the brain and the venous sinuses via 6 tortuous longitudinal channels. Finally, they drain into the internal vertebral venous plexus.