Mednotes.

Vasculature of the Spinal Cord

Arterial supply

  • Mainly comes from 2 sources
    1. Longitudinal arteries throughout the spinal cord (spinal arteries)
    2. Arteries along the spinal cord (segmental medullary arteries/radicular arteries)
  • The three longitudinal arteries supply the cord directly
    • These run longitudinally from medulla to conus medullaris
      • Run within the arachnoid mater
      • All three branch off the vertebral artery
    • 1x anterior spinal artery
      • Runs in the anterior median fissure
      • Gives off Sulcal arteries which enter the spinal cord through the fissure
      • Supply 2/3 of the SC’s thickness
    • 2x posterior spinal arteries (Right and Left)
      • Branch off either the PICA or vertebral artery
      • Form anastamoses in the pia mater

    • From https://commons.wikimedia.org/wiki/File:Gray770-vessels.png
      Arteries supplying the spinal cord – 1: Posterior spinal vein 2: anterior spinal vein 3: posterolateral spinal vein 4: radicular (or segmental medullary) vein 5: posterior spinal arteries 6: anterior spinal artery 7: radicular (or segmental medullary) artery
  • Vessels running along spinal nerves provide further circulation
    • 2 types of vessels
      1. Anterior and posterior segmental medullary arteries
        • Branch from spinal branches of several arteries
          1.  deep and ascending cervical
          2. Vertebral
          3. posterior intercostal
          4. and lumbar arteries
        • Enter into the spinal column via IV foramina
        • Most prominent with the lumbosacral/cervical enlargements
        • The great anterior segmental medullary artery is the biggest and occurs around the inferior thoracic/upper lumbar arteries
      2. Anterior and posterior radicular arteries supply the roots of the spinal nerves

 

 

 

 

Venous Supply

  • Unlike arteries,  there are 3 anterior and 3 posterior spinal veins
    • One posterior and two posterolateral veins
    • Three anterior spinal veins
    • These drain into medullary/radicular veins
  • The medullary/radicular veins join into internal vertebral venous plexuses that then pass into the cranium to communicate with the dural sinuses
    • Also communicate with external vertebral venous plexuses in the cervical region => drain into cervical, intercostal, and verterbal veins