part of cranial nerve structural organization accessory nerve morphogenesis accessory nerve structural organization CN XI structural organization biological_process GO:0021609 accessory nerve structural organisation The process that contributes to the act of creating the structural organization of the accessory nerve This process pertains to the physical shaping of a rudimentary structure. The spinal branch of this motor nerve innervates the trapezius and the sternocleidomastoid muscles. The cranial branch joins the vagus nerve and innervates the same targets as the vagus nerve.