(Depending on size)

  • Dermatomes are strips of skin which are supplied by the nerve roots. If there is numbness or pain along a dermatome, it is a sign of damage or irritation of a specific nerve root, where the root exits the spinal cord and vertebral column. This is known as radiculopathy.
  • Soon after the cervical and lumbosacral nerves leave the cord, they join and separate several times (plexi) before reaching their target organs. Nerve fibers to a given muscle may come from several different nerve roots. The skin sensory supply, however, remains directly associated with the root alone.
  • Radicular pain usually occurs with compression of the nerve in the foramen, the hole by which the nerve exits the spinal canal.