The Accessory Nerve (Cranial Nerve XI)

The eleventh cranial nerve is the accessory nerve. It is a motor nerve, responsible for innervating the sternocleidomastoid (SCM) and the trapezius muscles. The SCM is a muscle in the neck that allows rotation (looking side to side) and flexion (looking down) of the neck[1]. The trapezius muscle acts to shrug the shoulder.

References:

  1. https://en.wikipedia.org/wiki/Accessory_nerve#cite_ref-luc_2-0 Opens in new window
  2. "Spinal Accessory Nerve". Structure of the Human body, Loyola University Medical Education Network. Archived from the original on 16 June 2007. Retrieved 2007-06-17.