Exam 2 Study Material: Accessory and Hypoglossal Nerve (CN XI & XII) - Biology

CN XI is an exclusively _____ nerve

motor

What are the 2 roots of CN XI?

cranial and spinal

What muscles do cranial and spinal roots of CN XI contribute LMNs to?

-SCM

-trapezius

-muscles of soft palate

-larynx

-pharynx

The spinal nucleus of the accessory nerve is found in the _____ horn of gray matter

anterior

(TQ) Anterior horn of the gray matter expands from the level of the foramen magnum inferiorly to the ____ or ____ cord level

C5 ; C6

Apparent Origin of Cranial Root of CN XI

lateral aspect of medulla oblongata inferior to CN X

Cranial root of CN XI combines briefly with the spinal root and exits the skull through the ______

jugular foramen

Fibers from the cranial root separate from the spinal root and join the _____ at the inferior ganglion

vagus nerve

(TQ) Fibers of the cranial root of CN XI are distributed to the pharyngeal plexus and contribute motor supply to all laryngeal muscles EXCEPT:

cricoarytenoid muscle

Spinal Root of CN XI Apparent Origin

lateral aspect of the cord (C1-C5)

Rootlets from the spinal root of CN XI combine to form a trunk that will ascend between the denticulate ligaments and the posterior rootlets and enter the skull through the ______

foramen magnum

Spasmodic Torticolis

spasms of SCM - associated with CN XI

CN XII is an exclusively ____ nerve

motor

(TQ) Hypoglossal nerve supplies intrinsic and extrinsic muscles of the tongue, with the exception of the ______

palatoglossus

CN XII is formed by axons from cell bodies in the _______

nucleus of hypoglossal nerve

(TQ) Nucleus of hypoglossal nerve is located on the ______

floor of rhomboid fossa

CN XII Apparent Origin

sulcus between pyramid and olive

(TQ) Rootlets of CN XII combine to form two bundles and exit the skull through the ______

hypoglossal canal

Fibers of CN XII are distributed into terminal branches supplying muscles of the ____

tongue

(TQ) Some cervical fibers of CN XII will continue with the hypoglossal nerve to ultimately supply the _____ and ____ muscles

geniohyoid ; thyrohyoid

(TQ) Lingual fibers of CN XII are given off the hypoglossal nerve to supply the _____, _____, and ______ muscles

hyoglossus ; genioglossus ; styloglossus

Hemiatrophy is associated with which cranial nerve?

CN XII