The 11th cranial nerve which originates from NEURONS in the MEDULLA and in the CERVICAL SPINAL CORD. It has a cranial root, which joins the VAGUS NERVE (10th cranial) and sends motor fibers to the muscles of the LARYNX, and a spinal root, which sends motor fibers to the TRAPEZIUS and the sternocleidomastoid muscles.

Synonyms: Nerve XI, Cranial Nerve XI, Accessory Nerve, Spinal, Cranial Nerve, Eleventh, Nerve, Eleventh Cranial, Nervus Accessorius, Eleventh Cranial Nerves, Nerve, Accessory, Accessory Nerve, Nerves, Accessory, Nerves, Spinal Accessory, Accessorius, Nervus, Spinal Accessory Nerve, Spinal Accessory Nerves, Nerves, Eleventh Cranial, Nerve, Spinal Accessory, Accessory Nerves, Spinal, Cranial Nerves, Eleventh, Eleventh Cranial Nerve, Nerve XIs, Accessory Nerves