Anatomy of Spinal Cord


(Depending on size)

  • The spinal cord lies within the spinal canal, formed by the vertebral bodies and the bony arch formed by the pedicles and laminae (see M6).
  • The cord and its terminal nerves, the cauda equina, lie within the dural sac, a tough membranous structure filled with cerebrospinal fluid bathing and protecting the cord.
  • The spinal cord itself ends at the level of the first lumbar vertebra, but nerve roots travel inside the dural sac to exit at lower levels; these roots form the cauda equina (”horse’s tail”).
  • Blood supply comes from the segmental branches of the aorta, traveling along the nerve root to emerge as the anterior spinal artery running in the front midline of the cord; there are two parallel vessels along the back surface of the cord. There is also a generous venous plexus within the canal.