Cranial Nerves IX, X, XI, & XII!

Question 1

CN XII Axon type, Origin, Peripheral Termination…

Answer 1

Somatic motor
Hypoglossal nucleus (Exit adjacent to pyramid)
Tongue muscles (tongue Protrusion)

Question 2

Results of lesion of CN XII…

Answer 2

• Devotion of tongue towards lesion
• Fasciculations
• Atrophy

Question 3

Lesion on corticoblubar fibers of hypoglossal cause what?

Answer 3

• Deviation of tongue toward side opposite of lesion!
• No fasciculations
• Minimal atrophy

Question 4

CN XI lesion results in..

Answer 4

• Muscular atrophy of trapezius
• Weak shoulder shrug (Inability to express the fact that “you don’t know”)
• Scapula and clavicle “hang there”

Question 5

CN X Afferents are…

Answer 5

• Epiglottis taste and visceral sensation
• Thoracic & abdominal viscera
• Aortic arch baroreceptors blood pressure & chemoreceptors

Question 6

CN X Efferents are…

Answer 6

• Nucleus Ambiguus (lateral) = muscles of speech and swallowing.
• Nucleus Ambiguus (Medial) = heart and lungs
• Dorsal motor nucleus of vagus (all visceral up to transverse colon)

Question 7

What are the components of the “Gag Reflex”?

Answer 7

• CN IX = afferent component
• CN X = efferent component
• Central connections are not clear.

Question 8

What are the components of the tongue thrust reflex?

Answer 8

• CN V or IX - afferent limb
• Cn XII = efferent limb
• In infants to 8 years old potentially.

Question 9

What is Vasovagal Syncope?

Answer 9

A response to a trigger, vagus decreases heart rate & blood pressure = fainting and confusion.

Question 10

What is jugular foramen syndrome?

Answer 10

IX, X XI & XII are at risk for entrapment by a skull base tumor.

Question 11

Pain in ear could be a result of what nerves Entrapment?

Answer 11

IX, X

Question 12

Headache, meningeal irritation could be result of what nerve entrapment?

Answer 12

X

Question 13

Hoarseness can be a result of what nerve entrapment?

Answer 13

X

Question 14

Dysphagia can be result of what nerve entrapment?

Answer 14

X

Question 15

Horner syndrome (Ptosis, pupillary constriction) can be the result of which nerve entrapment?

Answer 15

Internal carotid nerve

Question 16

Loss of gag reflex can be the result of which nerve entrapment?

Answer 16

IX, X

Question 17

What is a hallmark sign of Jugular foramen syndrome?

Answer 17

• Uvula deflects to side that is contralateral to lesion.
• Arch of soft palate droops
• Wasting of tongue, deviates to side of lesion.

Question 18

Tell me about Glossopharyngeal Neuralgia….

Answer 18

• Similar to trigeminal neuralgia
• Rare but distressing
• Sudden burst of pain in posterior tongue or wall of pharynx, then radiates to ear.
• Triggered by swallowing or talking.

Question 19

CN IX Efferents are..

Answer 19

• Nucleus Ambiguus (stylopharengeus muscle and other pharyngeal and laryngeal muscles.)
• Inferior Salivary nucleus (otic ganglion –> parotid gland)

Question 20

CN IX Afferents are..

Answer 20

• Skin of ear & middle ear
• Post. 1/3 of tongue
• post. 1/3 tongue (taft and visceral sensation)
• Carotid body (blood, O2, CO2 & pH)
• Carotid sinus (Changes in blood pressure)
• Inferior Ganglion of glossopharyngeal nerve
• solitary nucleus