5. CN IX, X and XII Flashcards by J L

CN IX Glossopharyngeal Nerve

Rootlets of CN IX emerge from the medulla between the ____ and the ____

The nerve exits the cranial cavity through the ____

olive
inferior cerebellar peduncle
jugular foramen

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• Preganglionic parasympathetics (GVE)
to ____

• Special sensory fibers (SVA) from ____

• GVA fibers
from ____ and ____

• SVE fibers
to ____

• General sensory fibers (GSA) from Mucosa of:
• \_\_\_\_ 
• Auditory tube
• \_\_\_\_ 
• Oropharynx
• \_\_\_\_
• Soft palate
Skin of \_\_\_\_ and \_\_\_\_

otic ganglion
root (posterior 1/3) of tongue
carotid body
carotid sinus
stylopharyngeus

tmpanic cavity
root of tongue
fauces
auricle
tympanic membrane

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AFFERENTS
Cell bodies of all sensory neurons in this nerve, (GSA, GVA, SVA) are located in the
____ and ____
of CN IX located just above and below the
____

superior
inferior ganglia
jugular foramen

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The central processes of the pseudounipolar sensory neurons in the two ganglia project
as follows:
SVA fibers project to the ____

GVA fibers project to the ____

GSA fibers project to the ____

solitary nucleus (rostral)
solitary nucleus (caudal)
spinal trigeminal nucleus

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EFFERENTS
The lower motor SVE neuron cell bodies are found in the ____ of the medulla

Preganglionic paraympathetic neurons (GVE) are located in the
____ of the medulla

nucleus ambiguus

inferior salivatory nucleus

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Before descending into the deep neck by coursing posterior
to the styloid process, CN IX gives off the
____ and ____ nerves

tympanic nerve
carotid sinus nerve

tympanic

carotid sinus

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Tympanic Canaliculus

The TYMPANIC NERVE immediately re-enters the temporal bone via the ____ …and ramifies to form the ____ in the tympanic
cavity

tympanic canaliculus

tympanic plexus

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AFFERENT branches of the tympanic plexus
innervate mucosa lining the following:
\_\_\_\_
Auditory tube
\_\_\_\_

These nerves mediate the pain of ____ (middle ear infection)

tympanic cavity
mastoid air cells
otitis media

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The Lesser Petrosal

Nerve courses across the ____ and usually exits ____

middle cranial fossa

foramen ovale

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The
LESSER PETROSAL NERVE carries ____ parasympathetics to the
____

preganglionic

otic ganglion

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CN IX

BRANCHING AND NOTES!

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FREY’S SYNDROME -
____
____ - sympathetic

* Incision performed on vicinity of oracle and parotid gland
* Can also result in localized \_\_\_\_

gustatory
sweating
flushing

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The CAROTID SINUS NERVE
aka
____ Nerve

Contains GVA fibers from:
• ____ in the carotid sinus
• ____ in the carotid body

These inputs are ultimately relayed to both the ____ and the ____ for appropriate reflex responses controlling:
• ____
• B.P.
• ____

hering's
baroreceptors
chemoreceptors
hypothalamus
reticular formation
respiration
cardiac output

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A lesion of
HERING’S NERVE
may provoke fluctuations in ____ and ____……may occur as a result of surgical extirpation of malignant ____ lymph nodes

arterial blood pressure
heart rate
deep cervical

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Following the origin of the tympanic and carotid sinus nerves, multiple ____
unite with branches of CN X as well as postganglionic sympathetics
to form the
PHARYNGEAL
PLEXUS
near the ____

pharyngeal branches

middle pharyngeal constrictor

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Pharyngeal
branches of CN IX provides ____ innervation of mucosa lining the walls of the
____

Mechanical stimulation of the walls of the oropharynx produces a
____

sensory
oropharynx
gag reflex

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Pharyngeal ____ and palatal ____… accompanied by:

closure of the ____
thrusting of the ____
opening of the ____

Testing this reflex is the ONLY RELIABLE WAY to assess the integrity of
____ but… There is significant ____ in terms of presence/absence as well as strength of the
Gag reflex

constriction
elevation
glottis
tongue
mouth
CN IX
variation

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The nerve then gives rise to a ____ to the lone 3rd pharyngeal arch muscle (____)

muscular branch (SVE)
stylopharyngeus

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CN IX

The nerve then curves forward and enters the pharynx along with STYLOPHARYNGEUS between the ____ and ____

superior

middle pharyngeal constrictors

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If we strip away the mucosa lining the ____
and the ____,
we can follow CN IX as it approaches the ____ OF THE TONGUE

fauces
tonsilar fossa
posterior 1/3 (root)

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The nerve may thus be lesioned during tonsillectomy, eliminating ALL sensation from the ____ of the tongue

ipsilateral posterior 1/3

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The ____ BRANCH
supplies the palatine tonsil,
fauces and soft palate (GSA)

Two LINGUAL BRANCHES
Transmit ____ and ____ sensation from the posterior third of the tongue

tonsilar
general (GSA)
special (SVA)

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Recall that the posterior 1/3 of the tongue
lacks small ____, (featuring instead the nodules of lymphoid
tissue which collectively form the ____)

Gustatory and general sensory nerve endings in the posterior 1/3 convey information via both ____ and ____ fibers in the lingual branches of CN IX

papillae
lingual tonsil
general
special sensory

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CN X Vagus Nerve

Like CN IX, the Vagus leaves the medulla from the ____ by multiple rootlets

They are joined by the fibers of the “cranial root of CN ____” arising from ____ at the jugular foramen

postolivary sulcus
XI
nucleus ambiguus

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• Preganglionic parasympathetics (GVE) to ____ and ____ mucosa; ____ and ____ viscera • Special sensory fibers (SVA - taste) from ____ and valleculae (NOT SHOWN) * General sensory fibers (GSA) from ____ and auditory canal, PCF meninges, ____ and pharynx * SVE fibers to ____ and ____ arch muscles * GVA fibers from ____ of larynx, pharynx, heart, esophagus, GI tract, trachea, bronchi, lungs; also ____ receptors

pharyngeal laryngeal thoracic abdominal epiglottis auricle larynx 4th 6th visceroreceptors

SVE fibers arise from the ____ GVE Fibers arise from the ____ ``` The SUPERIOR (JUGULAR) and INFERIOR (NODOSE) GANGLIA are exclusively ____: The JUGULAR is concerned with ____ sensation The NODOSE with ____ sensation ```

``` nucleus ambiguus dorsal vagal nucleus sensory somatic visceral ```

The vagus nerve innervates pharyngeal and laryngeal musculature derived from the ____ and ____ pharyngeal arches

4th | 6th

``` THREE main branches of CN X distribute SVE fibers arising from NUCLEUS AMBIGUUS - Pahryngeal Joins CN IX to form the ____ - Superior laryngeal - ____ ``` Recall that many of these fibers actually leave the medulla in the “____” of CN XI before joining the VAGUS

pharyngeal plexus recurrent (inferior) laryngeal cranial root

The Pharyngeal Nerve | innervates most ____ and ____ musculature

pharyngeal | palatal

EXCEPTIONS TO CN X INNERVATION: Pharynx - Stylopharyngeus - CN ____ Palate - Tensor veli palatini - CN ____

IX | V3

____ VAGAL LESIONS COMMONLY RESULT IN ABNORMAL GAG Asymmetry in palatal elevation will be observed on phonation, swallowing or laryngoscopy due to paralysis of the ipsilateral ____ Patient experiences nasal speech and nasal ____ of liquids Involvement of the ____ may result in DYSPHAGIA

unilateral LVP reflux constrictors

Superior Laryngeal Nerve (CN X) The external branch innervates the ____ The internal branch pierces the ____ ligament between hyoid bone and thyroid cartilage

cricothyroid | thyrohyoid

The EXTERNAL BRANCH of the SUPERIOR LARYNGEAL NERVE Also sends twigs to the ____

inferior pharyngeal constrictor

Surgical excision of the thyroid gland involves ligation of the ____ THYROID ARTERY and endangers the ____ BRANCH of the SUPERIOR LARYNGEAL N. If cut, the patient will present with WEAK, ____ SPEECH WITH ____ PITCH

superior external monotonous decreased

The RECURRENT LARYNGEAL NERVES innervate all intrinsic laryngeal muscles with the exception of the ____... and provides ____ innervation to mucosa of the ____ larynx

cricothyroid sensory infraglottic

The courses of the left and right RECURRENT LARYNGEAL NERVES ____ significantly ____ are vulnerable to pathology or excision of the thyroid gland

differ | both nerves

``` The ____ RECURRENT LARYNGEAL NERVE is vulnerable to ____ or ____ pathology • ____ aneurysm or dissection • Lung cancer (pancoast tumor) • ____ resection ```

``` left mediastinal pulmonary aortic arch lung (lobar) ```

Superior thyroid artery Inferior thyroid artery Ligation of the thyroid arteries in thyroidectomy endangers the ____

laryngeal nerves

Ligation of the | ____ THYROID ARTERY endangers the ____ NERVE

inferior | recurrent laryngeal

``` Injury to either RECURRENT LARYNGEAL NERVE results in ____ or ____ of most laryngeal muscles, producing: • LESS ____ OR FIXED, ____ VOCAL CORD • ROUGH, RASPY ____ ``` THE RECURRENT LARYNGEAL NERVE (CN X) in the ____

``` paresis paralysis mobile adducted hoarseness trachea-esophageal groove ```

With recurrent laryngeal nerve injury the vocal fold usually assumes an ____ postiton. In unilateral paralysis, the voice may be hoarse and breathy, but the airway is usually not obstructed because normal fold ____ sufficiently.

adducted paramedian | abducts

VAGAL AFFERENTS - ____ - ____

auricular | meningeal

MASTOID CANALICULUS Transmits the ____ of CN X

auricular branch

The AURICULAR BRANCH of CN X which enters the ____ emerges from the temporal bone through the... ____

mastoid canaliculus | tympanomastoid fissure

The AURICULAR BRANCH is the only ____ branch of the Vagus nerve It mediates the pain of ____ ("swimmer's ear") resulting from ____ infection following loss of cerumen "Ear cough" reflex? (____ reflex) Produced by vagal afferent ____

otitis externa bacterial arnold hypersensitivity

Internal branch of the superior laryngeal nerve Innervates mucosa of the ____ and mediates the ____ of the cough reflex Initiated by either ____ or ____ stimulation of local epithelium

supraglottic larynx afferent limb mechanical chemical

INTERNAL BRANCH of the SUPERIOR LARYNGEAL nerve The nerve also innervates mucosa lining the ipsilateral ____ and ____

vallecula | piriform recess

The INTERNAL LARYNGEAL nerve mediates sensation from the mucosa of the ____ larynx as well as the ____ and the ____ So... the nerve serves as the ____ of the cough reflex

supraglottic piriform sinus vallecula afferent limb

The RECURRENT (INFERIOR) LARYNGEAL NERVES mediate sensation from mucosa of the ____ larynx

infraglottic

- Internal laryngeal nerve - ____ - Recurrent laryngeal nerve

Galen's anastomosis

The vagus is also responsible for the sensory innervation of the ____ via ____ in the pharyngeal nerve

laryngopharynx | afferents

SVA fibers mediate taste sensation from the EPIGLOTTIS and VALLECULA via the ____ nerve These too project to the ____

internal laryngeal | solitary nucleus

GVA fibers, many of which convey sensations of visceral ____, also course along with vagal ____ Some of these visceral afferents also convey physiologic sensations arising from... ____ responding to distension in the walls of the GI tract, respiratory structures and bladder as well as baroreceptors in arteries ____ responding to changes in the partial pressure of O2 and CO2 in the blood, changes in blood pH and changes in the concentration of hydrogen ions in the stomach

pain parasympthetics mechanoreceptors chemoreceptors

Branching for CNX UPLOAD!

In order to reach the thorax and abdomen, CN X courses through the deep neck within the ____ As CN X approaches the mediastinum, it contributes branches to both ____ and ____

carotid sheath cardiac plexus pulmonary plexus

CN XII – Hypoglossal Nerve Numerous rootlets arise from the ____ of the medulla and converge on the ____ CANAL

pre-olivary sulcus | hypoglossal

The long, thin Hypoglossal Nucleus containing the cell bodies of the ____ of CN XII is located in the medulla in the floor of the ____ ventricle The nucleus extends the full length of the ____ and gives rise to ____ rootlets

LMN fourth medulla 10-15

Posterior cranial fossa CN XII rootlets courses across the anterolateral aspect of foramen magnum to reach the ____ ____ CANAL transmits CN XII

hypoglossal canal | hypoglossal

After exiting the hypoglossal canal, CN XII courses inferiorly and laterally between the ____ and the ____… ...where it is closely related to CN ____, ____ and the ____ ganglion...

``` ICA IJV X C1 superior cervical ```

The nerve continues on the lateral surface of the hyoglossus ... within the ____ ... passes above the free posterior border of the ____... ``` ...and divides to supply: • ____ • Styloglossus • ____ • All ____ tongue muscles ```

``` digastric triangle mylohyoid hyoglossus genioglossus intrinsic ```

In following the course just described, CN XII lies inferior to the two sensory nerves of the tongue: ____ (V3) and ____ (CN IX)

``` lingual nerve (V3) glossopharyngeal (CN IX) ```

CN XII lies very deep to the ____ of the floor of the mouth - Submandibular duct (Wharton's duct) - Lingual nerve CN V3 - Hyoglossus - CN XII - Mylohyoid

oral mucosa

Medial to the hyoglossus (CUT)… runs the ____, often described as accompanying CN ____

lingual artery | XII

CN XII is vulnerable to iatrogenic injury in the increasingly common procedure known as ____… ...as well as compression resulting from ____ or ____

carotid endarterectomy carotid artery aneurysm dissection

Recall that CN XII is accompanied by fibers of the ____ ventral ramus which leave in the ____

C1 | descendens hypoglossi

Do you remember the ____ muscles? They are critical to the clinical assessment of CN XII

genioglossus

CN XII LESIONS The integrity of CN XII is tested by asking the patient to ____ the tongue and observing the results

protrude

CN XII Lesions Also... • ____ • Fibrillations and fasciculations (twitching) • ____ (mild) (particular difficulty with lingual consonants ____, ____ and ____) • Oral transport weakness With a unilateral lesion of CN XII... The protruded tongue will deviate TO THE SIDE OF THE ____ as the functional genioglossus is unopposed

``` ipsilateral atrophy dysarthria D T L lesion ```

Lesions of CN XII - tumors or meningiomas of the ____ cranial fossa or ____ - ____ aneurysm or dissection below the skull base - ____ puncture below the skull base - lesions within the ____ space or tongue - - ____ (i.e. squamous cell carcinoma arising from base of tongue or floor of mouth) - - ____ (odontogenic abcess in sublingual space) - - ____ from oral surgery along the floor of the mouth

``` posterior nasopharynx ICA IJV sublingual neoplasm infection iatrogenic ```