Cranial roots of accessory nerve

Cranial roots of accessory nerve
Brain stem sagittal section (11 visible near bottom center. In this diagram, the root derives entirely from the spinal portion, and ascends to the cranium.)
Plan of upper portions of glossopharyngeal, vagus, and accessory nerves.
Details
Identifiers
Latinradix cranialis nervi accessorii, pars vagalis nervi accessorii
TA98A14.2.01.185
TA26353
FMA77543
Anatomical terms of neuroanatomy

The cranial roots of the accessory nerve or vagal part, is the smaller of the two portions of the accessory nerve. It is generally considered as a part of the vagus nerve and not part of the accessory nerve proper because the cranial component rapidly joins the vagus nerve and serves the same function as other vagal nerve fibers. The concept of a cranial root of the accessory nerve was challenged by neuroanatomical studies which found that an unambiguous cranial root was not present in the majority of cases, but a small study in 2007 followed by a substantially larger study published in 2012 both confirmed that the cranial root of the accessory nerve is commonly found in humans, matching traditional descriptions.