CN XII

Question 1

What is the name of CN XII?

Answer 1

hypoglossal nerve

Question 2

What number is the hypoglossal nerve?

Answer 2

CN XII

Question 3

How is the hypoglossal nerve classified?

Answer 3

exclusively motor

Question 4

What does CN XII innervate?

Answer 4

intrinsic and extrinsic muscles of the tongue

NOT palatoglossus

Question 5

What type of fibers are in CN XII?

Answer 5

LMN’s somatic motor fibers

Question 6

What CN’s carry sensation from the area supplied by CN XII?

Answer 6

CN; V, VII, IX

Question 7

Where are cell bodies of CN XII found?

Answer 7

nucleus of the hypoglossal nerve

Question 8

Where is the nucleus of the hypoglossal nerve found?

Answer 8

floor of the rhomboid nucleus

Question 9

What is another name for the nucleus of the hypoglossal nerve?

Answer 9

“hypoglossal nucleus”

Question 10

What is the apparent origin of CN XII?

Answer 10

series of rootlets in the sulcus between the pyramid and olive of the medulla oblongata

Question 11

How does CN XII exit the skull?

Answer 11

hypoglossal canal

Question 12

How does CN XII travel after exiting the hypoglossal canal?

Answer 12

descends forming a loop to reach teh base of the tongue

Question 13

What is the loop of CN XII nerve called?

Answer 13

arch of the hypoglossal nerve

Question 14

After the hypoglossal nerve reaches the base of the tongue what does it do?

Answer 14

terminal branches reach the muscles of the tongue

Question 15

What fibers travel with but aren’t part of the hypoglossal nerve?

Answer 15

C1 and C2 fibers

Question 16

When the C1 and C2 fibers separate from the hypoglossal nerve what do they form?

Answer 16

superior root of the ansa cervicalis

Question 17

What do the cervical fibers that continue with the hypoglossal nerve innervate?

Answer 17

geniohyoid and thyrohyoid muscles

Question 18

What do the lingual branches of the hypoglossal nerve innervate?

Answer 18

hyoglossus, genioglossus, and styloglossus muscles

Question 19

What muscle is not innervated by the hypoglossal nerve?

Answer 19

palatoglossus nerve

Question 20

How can the tongue be used to diagnose problems with the hypoglossal nerve?

Answer 20

tongue will not stick out straight

Question 21

What direction does the tongue point with hypoglossal nerve damage?

Answer 21

points to the damaged side

HEMIATROPHY

Question 22

How can swallowing be evaluated for hypoglossal nerve damage?

Answer 22

the larynx will deviate to the “normal” unaffected side