The spinal cord circulation is derived from segmental branches arising from the vertebral arteries, as well as multiple radicular arteries arising from segmental vessels in parallel, including the descending cervical, deep cervical, intercostal, lumbar, and sacral arteries. The venous drainage of the spinal cord is more symmetric and redundant when compared to the arterial system with both minimal anterior to posterior and right to left segmental variation. 

Spinal Arterial System

Embryology Overview

Vertebral artery

• Embryogenesis between approximately day 32 and day 40
• Formed from fusion of the longitudinal anastomoses that link cervical intersegmental arteries, which branch from the primitive paired dorsal aorta
• Intersegmental arteries regress
• The seventh Intersegmental arteries...