Cranial Nerves XI & XII

Question 0

Where are the cell bodies located from the cranial root of the accessory nerve?

Answer 0

Nucleus ambiguus

Question 1

What do both roots of the accessory nerve supply?

Answer 1

SCM, trapezius, and muscles of the soft palate, pharynx, and larynx

Question 2

Where is the spinal nucleus of the accessory nerve located?

Answer 2

Anterior horn of the gray matter between the foramen magnum and the C5/C6 level

Question 3

Does the accessory nerve contain any sensory fibers?

Answer 3

No, purely motor

Question 4

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

Answer 4

Lateral aspect of the medulla oblongata (as a series of rootlets)

Question 5

Through what osseous opening does the accessory nerve exit the cranial vault?

Answer 5

Jugular foramen

Question 6

When does the cranial root of the accessory nerve separate from the spinal root?

Answer 6

After exiting the skull through the jugular foramen (leaving the CNS)

Question 7

After leaving the CNS through the jugular foramen, where do the fibers of the cranial root of the accessory nerve travel to?

Answer 7

Join the vagus nerve at the inferior ganglion and are distributed to the pharyngeal plexus, external laryngeal nerve, and recurrent laryngeal nerve

Question 8

After joining with the vagus nerve and some branches, the cranial root of the accessory nerve helps to contribute supply to which muscles?

Answer 8

All laryngeal muscles except cricoarytenoid

Question 9

What are the two roots of the accessory nerve?

Answer 9

Cranial and spinal roots

Question 10

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

Answer 10

Lateral aspect of the cervical cords between the anterior and posterior rootlets

Question 11

What is the pathway of the spinal root before it combines with the cranial root?

Answer 11

Rootlets form a trunk that ascends between the posterior rootlets and denticulate ligaments to then enter the skull through the foramen magnum

Question 12

When the spinal root combines with the cranial root of the accessory nerve, it travels through what osseous opening?

Answer 12

Jugular foramen

Question 13

The spinal root of the accessory nerve traverses what triangle of the neck?

Answer 13

Posterior triangle

Question 14

After exiting the jugular foramen with the cranial root, what muscles are supplied by the spinal root of the accessory nerve?

Answer 14

SCM, trapezius

Question 15

Which muscle is supplied by the spinal root of the accessory nerve before it traverses the posterior triangle?

Answer 15

Sternocleidomastoid

Question 16

Which muscle is supplied by the spinal root of the accessory nerve after it traverses the posterior triangle?

Answer 16

Trapezius

Question 17

There is considerable evidence to suggest that what nerves also supply the trapezius muscle?

Answer 17

Cervical plexus

Question 18

When divided out, what nerves supply the separate parts of the trapezius muscle?

Answer 18

Cranial nerve XI supplying upper and middle portion

Cervical plexus supplying lower 2/3

Question 19

What nerve is most likely responsible for the sensory information (proprioception) of the trapezius muscle?

Answer 19

Cervical plexus (NOT cranial nerve XI)

Question 20

The spinal nucleus of the accessory nerve is the cell body location for fibers from which root?

Answer 20

Spinal root

Question 21

What is the primary difference between the spinal nucleus of the accessory nerve and the spinal nucleus of the trigeminal nerve?

Answer 21

Spinal nucleus of the trigeminal nerve is sensory in function & therefore a nucleus of termination; spinal nucleus of the accessory nerve is a nucleus of origin and motor in function

Question 22

What spinal tract is likely to synapse in the location of the spinal nucleus of the accessory nerve (anterior horn of the gray)?

Answer 22

Tectospinal tract

Question 23

Paralysis of what muscle can result with interruption to the spinal component of the accessory nerve and what action is impaired?

Answer 23

SCM is paralyzed; the patient is unable to turn their head to the opposite side

Question 24

Interruption of the spinal component of the accessory nerve has what effect on the trapezius and brachial plexus?

Answer 24

Traction due to the trapezius’ inability to support the scapula

Question 25

What is spasmodic torticollis?

Answer 25

Episodic spasm of SCM and trapezius

Question 26

What general muscles are supplied by the hypoglossal nerve?

Answer 26

Intrinsic and extrinsic muscles of the tongue

Question 27

What is the exception to the motor supply for the hypoglossal nerve and is therefore NOT supplied by it?

Answer 27

Palatoglossus muscle

Question 28

What is the nucleus of origin for cranial nerve XII?

Answer 28

Hypoglossal nucleus

Question 29

What is the location of the hypoglossal nucleus?

Answer 29

Floor of the rhomboid fossa in the medulla oblongata

Question 30

What is the apparent origin of cranial nerve XII?

Answer 30

Sulcus between the pyramids and olives of the medulla oblongata

Question 31

Through what osseous opening does cranial nerve XII exit the skull?

Answer 31

Hypoglossal canal

Question 32

What is the loop formed by cranial nerve XII as it descends to reach the base of the tongue?

Answer 32

Arch of the hypoglossal nerve

Question 33

What specific fibers travel with but don’t become incorporated into the hypoglossal nerve?

Answer 33

Fibers from the first and second cervical nerves (C1 & C2)

Question 34

What muscles are supplied by some of the cervical fibers that continue to travel with the hypoglossal nerve instead of becoming the superior root of the ansa cervicalis?

Answer 34

Geniohyoid and thyrohyoid muscles

Question 35

What muscles are supplied by the lingual branches of the hypoglossal nerve?

Answer 35

Hypoglossus, genioglossus, and styloglossus