====== SPINAL CORTEX OR PERIPHERY ======


  * spinal cortex or periphery is mainly formed by white matter 
    * outer row and columns containing tracts , relay fibers 
      * ascending tracts 
      * descending tracts 
    * crossing of fibers / nerve tracts at level 
      * spinal row 
      * medulla row 
    * inside spinal cord 
      * interneurons