"The accessory nerve, also called the spinal accessory nerve, or historically, the nerve of Willis, is the eleventh cranial nerve (CN XI) and is composed of two parts, the cranial part and the spinal part (TA: nervus accessorius or nervus cranialis XI)."
"The cranial part (accessory portion) is the smaller of the two. Its fibres arise from the cells of the nucleus ambiguus and emerge as four or five delicate rootlets from the side of the medulla oblongata, below the roots of the vagus nerve. It runs laterally to the jugular foramen, where it interchanges fibres with the spinal portion or becomes united to it for a short distance; here it is also connected by one or two filaments with the jugular ganglion of the vagus. It then passes through the jugular foramen, separates from the spinal portion and continues over the surface of the ganglion nodosum of the vagus, to the surface of which it is adherent, and is distributed principally to the pharyngeal and superior laryngeal branches of the vagus. Through the pharyngeal branch, it probably supplies the musculus uvulae and levator veli palatini. Some filaments from it continue into the trunk of the vagus below the ganglion, to be distributed with the recurrent nerve and probably also with the cardiac nerves."
"The spinal part (spinal portion) is firm in texture. Its fibres arise from the ventral horn cells in the cord between C1 and C5 of the cervical plexus. The fibres emerge from the cord laterally between the anterior and posterior spinal nerve roots to form a single trunk, which ascends into the skull through the foramen magnum. It then exits the skull through the jugular foramen, through which it passes, lying in the same sheath of dura mater as the vagus but separated from it by a fold of the arachnoid mater."
Expected headings
"Connections and course"
"Functions"
"Clinical landmarks"
"The cranial part (accessory portion) is the smaller of the two. Its fibres arise from the cells of the nucleus ambiguus and emerge as four or five delicate rootlets from the side of the medulla oblongata, below the roots of the vagus nerve. It runs laterally to the jugular foramen, where it interchanges fibres with the spinal portion or becomes united to it for a short distance; here it is also connected by one or two filaments with the jugular ganglion of the vagus. It then passes through the jugular foramen, separates from the spinal portion and continues over the surface of the ganglion nodosum of the vagus, to the surface of which it is adherent, and is distributed principally to the pharyngeal and superior laryngeal branches of the vagus. Through the pharyngeal branch, it probably supplies the musculus uvulae and levator veli palatini. Some filaments from it continue into the trunk of the vagus below the ganglion, to be distributed with the recurrent nerve and probably also with the cardiac nerves."
"as it exits from the jugular foramen, it runs backwards then descends obliquely behind the digastric and stylohyoid muscles to the upper part of the sternocleidomastoid muscle; it pierces this muscle and courses obliquely across the posterior triangle of the neck, to end in the deep surface of the trapezius muscle"