accessory nerve trunk

ac·ces·so·ry nerve trunk

[TA] part of the accessory nerve formed within the cranial cavity by the union of the traditional cranial and spinal roots, which then divides within the jugular foramen into internal and external branches, the former uniting with the vagus, the latter exiting the foramen as an independent branch that is commonly considered to be the accessory nerve. The validity of the concept of a cranial root of the accessory nerve has been questioned as well as the common existence of its trunk. Recent studies claim the "cranial root" is always part of the vagus nerve. Synonym(s): truncus nervi accessorii [TA]

ac·ces·so·ry nerve trunk

(ak-sesŏr-ē nĕrv trŭngk) [TA] Part of the accessory nerve formed within the cranial cavity by the union of the traditional cranial and spinal roots, which then divides within the jugular foramen into internal and external branches, the former uniting with the vagus, the latter exiting the foramen as an independent branch commonly considered to be the accessory nerve. Validity of the concept of a cranial root of the accessory nerve has been questioned as well as the common existence of its trunk. Recent studies claim the "cranial root" is always part of the vagus nerve.