CN XI

Question 1

What is the name of CN XI?

Answer 1

Accessory nerve

Question 2

What number is the accessory nerve?

Answer 2

CN XI

Question 3

How is CN XI classified?

Answer 3

exclusively motor

Question 4

How many roots does CN XI have?

Answer 4

two

Question 5

What are the two roots of the accessory nerve?

Answer 5

cranial and spinal roots

Question 6

What do the cranial and spinal roots contribute?

Answer 6

LMN’s

Question 7

What do the cranial and spinal accessory roots innervate?

Answer 7

SCM, trapezius, muscle of the soft palate, pharynx, larynx

Question 8

Where are the cell bodies of the cranial root of the accessory nerve found?

Answer 8

nucleus abiguus

Question 9

Where is the spinal nucleus of the accessory nerve found?

Answer 9

anterior horn of the gray from level of the foramen magnum to C5/C6 cord level

Question 10

Where is the apparent origin of the cranial root of the accessory nerve?

Answer 10

lateral aspect of the medulla oblongata

Question 11

T/F: the spinal and cranial roots combine briefly traveling through the jugular foramen?

Answer 11

true

Question 12

How does the cranial root exit the skull?

Answer 12

jugular foramen

Question 13

Where do the cranial root and the spinal root split?

Answer 13

outside the skull

Question 14

What else does the cranial root join with and where? (hint: not spinal root)

Answer 14

vagus nerve at inferior (nodose) ganglion

Question 15

Where are the cranial nerve fibers that join with the vagus nerve distributed to?

Answer 15

pharyngeal plexus, external and recurrent laryngeal nerves

Question 16

What do the cranial root fibers with the vagus nerve innervate?

Answer 16

laryngeal muscles, but NOT cricoarytenoid

Question 17

T/F: the cranial root fibers are exclusively motor fibers?

Answer 17

false

Question 18

What is the apparent origin of the spinal root of the accessory nerve?

Answer 18

lateral aspect of the cervical cord C5/C6 level between the anterior and posterior rootlets

Question 19

Where does the trunk formed by the spinal root travel and in what direction?

Answer 19

ASCEND between the denticulate ligaments and in the posterior rootlets

Question 20

How does the spinal rootlet enter the skull?

Answer 20

foramen magnum

Question 21

What does the spinal root pass deep to and innervate?

Answer 21

sternocleidomastoid

Question 22

After the nerve travels in the posterior triangle in travels deep to and innervates what?

Answer 22

trapezius

Question 23

The trapezius receives innervation from the spinal root of accessory nerve and from what other probable source?

Answer 23

cervical plexus

Question 24

What part of the trapezius does the spinal root of the accessory nerve supply?

Answer 24

upper and middle portions

Question 25

What part of the trapezius of does the cervical plexus supply?

Answer 25

lower 2/3 of the muscle

Question 26

What is spasmodic torticollis?

Answer 26

clinical problem with the accessory nerve

episodic contraction of the SCM and trapezius

Question 27

What happens with interuption of the spinal nerve roots?

Answer 27

SCM paralysis: unable to turn face to contralateral side

R SCM issue = no L face turn

Question 28

What happens if the trapezius cannot function?

Answer 28

unable to support the upper extremity

BRACHIAL PLEXUS tractioned = upper part damaged first