Cranial Nerves IX-XII Flashcards Preview

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Flashcards in Cranial Nerves IX-XII Deck (31)
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1
Q

CN XII has its origin where?

A

In the hypoglossal nucleus

2
Q

What muscle is responsible for tongue protrusion?

A

The genioglossus muscle

3
Q

Where does CN XII exit the brainstem?

A

It exits adjacent to the pyramid

4
Q

What is the result of a hypoglossal nerve lesion (lower motor neuron)? (3 things)

A
  1. The tongue deviates towards the lesion
  2. Fasciculations
  3. Atrophy
5
Q

Does the hypoglossal nerve have corticobulbar fibers?

A

Yep

6
Q

If you have a corticobulbar (upper motor neuron) lesion, what can you expect to see? (3 things)

A
  1. Deviates toward opposite side
  2. No fasciculations
  3. Minimal atrophy
7
Q

What is the difference between an upper motor neuron and a lower motor neuron lesion associated with the tongue?

A

They are basically opposites- upper motor neuron lesions deviate towards the opposite side, no fasciculations and minimal atrophy are observed, and lower motor neurons are exactly the opposite

8
Q

Where is the origin of CN XI?

A

In the cervical spinal cord, not anywhere on the brainstem

9
Q

What is the result of an accessory nerve lesion? (4 things)

A
  1. Paralyzed trapezius
  2. Scapula and clavicle hang due to weak traps
  3. Weak shoulder shrug because levator scapulae is left all by itself
  4. Muscle atrophy leads to a scalloped appearance of the neck contour
10
Q

For CN IX, which nucleus sends fibers to the skin of the outer ear?

A

The superior ganglion of IX

11
Q

What are a few structures found in the rostral medulla concerning CN IX?

A

A lot of CN IX structures:
spinal trigeminal tract & nucleus
Solitary nucleus and tract
Vicinity of the inferior salivatory and ambiguus nuclei

12
Q

What are the CN IX afferents of the skin of the ear and the middle ear as well as taste to the posterior 1/3 of the tongue?

A

The superior ganglion of CN IX nerve

The trigeminal spinal nucleus

13
Q

CN IX is responsible for taste on what portion of the tongue?

A

Posterior 1/3

14
Q

The carotid body measures blod O2, CO2 and pH. The carotid sinus monitors changes in blood pressure. What nerve afferents are responsible for conveying this information?

A

CN IX via the inferior ganglion of CN IX and the solitary nucleus

15
Q

We’ve got some CN IX efferents via the nucleus ambiguus and the inferior salivatory nucleus. What is each responsible for?

A

Nucleus ambiguus:
- styolopharyngeus muscle and other pharynx and larynx muscles
Inferior salivatory nucleus:
- goes to the otic ganglion and then to the parotid gland

16
Q

What is glossopharyngeal neuralgia?

A

It’s similiar to trigeminal neuralgia. Sudden bursts of pain start in the posterior tongue or wall of the pharynx which then radiates to the ear. There is a trigger zone on the tongue or pharynx, so attacks are brought on by swallowing or talking.

17
Q

How is glossopharyngeal neuralgia treated?

A

There are some pills you can take or you can get a tractotomy of the spinal trigeminal tract in the caudal medulla

18
Q

T/F CN IX and X have a lot of similar origins and terminations?

A

Truth

19
Q

What are a few structures found in the rostral medulla concerning CN X?

A

Spinal trigeminal nucleus and tract
Dorsal motor nucleus of vagus
Solitary nucleus and tract
Vicinity of the nucleus ambiguus

20
Q

CN X afferents for the skin of the ear are served by what 2 things?

A
  1. Superior ganglion of CN X

2. Trigmeinal spinal nucleus

21
Q

What two types of afferents are found in the epiglottis that are associated with CN X?

A

Taste

Visceral sensation

22
Q

CN X afferents are also responsible for the aortic arch, baroreceptors, blood pressure and chemoreceptors via which 2 structures?

A
  1. Inferior ganglion of vagus nerve

2. Solitary nucleus of vagus nerve

23
Q

The vagus nerve has many efferents. What are the three things that are innervated via which nuclei?

A
Nucleus ambiguus (lateral)- muscles of speech and swallowing
Nucleus amiguss (medial)- heart and lungs
Dorsal motor nucleus of the vagus- all viscera up to the transverse colon
24
Q

In the gag reflex, which nerve is the afferent and which nerve is the efferent component of the gag reflex?

A

Afferent: CN IX
Efferent: CN X

25
Q

Tongue thrust reflex- the efferent limb is from which CN?

A

CN XII

26
Q

The tongue thrust reflex, if it persists can contribute to what?

A

Speech and orthodontic issues

27
Q

What is vasovagal syncope?

A

It is a response to a trigger- the vagus decreases heart rate and blood pressure and the person faints

28
Q

How is vasovagal syncope treated?

A

With a vagal nerve stimulator

29
Q

What is jugular foramen syndrome?

A

It is when CN IV, X, XI, XII are at risk of entrapment by a skull base tumor

30
Q

What are some symptoms of Jugular foramen syndrome?

A
pain in the ear
headache, meningeal irriation
hoarseness
dysphagia
horner syndrom
loss of gag relfex
31
Q

What are the hallmark symptoms (visible signs) of jugular foramen syndrome?

A
  • Uvula deflects to contralateral side
  • Inability to adduct vocal cord to midline
  • Arch of soft palate droops
  • Orophayrngeal sensory loss
  • Wasting away of the tongue, deviates to the side of the lesion on protrusion