CN V, VII, IX, XI, XII Flashcards Preview

Clinical Neuroscience weeks 1-3 > CN V, VII, IX, XI, XII > Flashcards

Flashcards in CN V, VII, IX, XI, XII Deck (41):

Trigeminal nerve contains what kind of fibers

sensory and motor


WHere is the nucleus of CN V located

Trigeminal nucleus called motor nucleus of V and is located mid pons


Travel of CN V

Motor fibers of CN V travel with the mandibular branch of CN V.
CN V exits the skull through the foramen ovale


CN V innervates what

Muscles of mastication and the temporalis muscles


Jaw Reflex is what

tappng gently on the lower jaw causes spindles in the masseter muscle to send an impulse through the sensory fibers of sensory cranial nerve V and synapse in the mesencephalic nucleus of V. A short interneuron connects the MESENCEPHALIC nucleus with the motor nucleus to send an impulse to the masseter muscle to contract.


Test CN V how

Have pateint bite down on tongue depressor and test jaw strength. Palpate the masseter and temporalis muscles.


Upper motor neuron to the CN V is ------, thus unilateral lesions to motor cortex ------ produce unilateral weakness of the jaw

Bilateral, Do not produce unilateral weakness of the jaw, although jaw reflex may be encreased


Lesions of CN V will cause

unilateral weakness of the jaw


CN VII carries what type of nerve fibers

motor, sensory, parasympathetic


Nucleus is where

rostral medulla


What the fuck is the superior salivary nucleus

It is the parasympathetic aspect of CN VII. lies right below CN VII nucleus pretty much. travels via nervus intermedius


CN VII and nervus intermedius exit the brainstem where?

pontomedullary junction called cerebellopontine angle


What is facial colliculi

A bulge on the flor of the fourth ventricle caused by the facail nerve fibers coming over the abducens nerve fibers bfore turning lateral and anterior to exit the brainstem.


Where does the CNVII exit the skull

Courses through teh internal audiotry meatus before turnign ventrally and exiting out the stylomastoid formen


Testing for CN VII

- wrinkle your fucking forehead
- show your teeth
- close eyes tightly


Upper motor neuron input to cranial nerve VII is bilateral for the forehead muscles but unilateral for the facial muscles. Thus a unilateral lesion to the motor cortex would present how

No symptoms in the forehead but ipsilateral weakness in the face


Unilateral lower motor neuron lesions of CN VII cause what

Ispilateral face and forehead weakness.

May also have dry eye and hyperacusis


Common cause of one sided facial paralysis due to trigeminal infection

Bells palsy


Motor nerve VII also controlscorneal do you test this

gently stroke cornea and observe eye closure


CN IX nucleus

Glossopharyngeal nerves nucleus is the nucleus ambiguus located near the junction of the pons and medulla (pontomedullary junction


CN IX innervates what

Innervates the stylopharyngeus muscle which raises the pharynx and larynx


Inferior salivatory nucleus sends preganglionc parasympathetic fibers out via CN IX to the what nerve

Lesser petrosal,,, then synapses in otic ganglion and goes to parotid gland


CN IX exits skull through what foramen

Jugular foramen


Describe the nucleus of the vagus nerve

Two nuclei:
1) Nucleus ambiguus- innervates soft palate, pharynx, larynx

2) Dorsal nucleus: Sends preganglonic parasympathetic fibers to the intramural ganglia assoc with heart, lung, and giestive tract


X eexits the calvarium via

The jugular foramen


Motor fibers of X which innervate the pharynx do what

Raise it during talking and swallowing


What nerves participate in gag reflex

9 and 10


Unilateral lesions in the nucleus ambiguus or CN X will cause

dysphagia due to an inability to elevate the palate on teh ipsilateral side


Substantial bilateral upper motor neuron innervation means...

unilateral upper motor neuron lesions tend to produce less prominent symptoms


CN V (motor) innervates what

masseter and temporalis (mastication)
tensor tympani (dampens sound)
Tensor Veli palatini (opens eustachian tube)
Inferior belly of digastric


CN VII innervates

muscles of facial expression and stapedius (dampens sound)


CN XI ( Spinal Accessory nerve) does what

Pure motor nerve that controls head turning via innervation of the Sternocleidomastoid muscles and shoulder elevation through the trpezius


Spinal nerve XI receives motor neuron input from what nuclei

Nucleus ambiguous and spinal accessory nucleus


Spinal accessory nucleus located where

intermediolateral gray area of between dorsal and ventral horns of the first 4-5 segments of spinal cord. Enter the calvarium through foramen magnum


Lesion of the lower motor neuron of CN XI (the nerve itself or its nuclei) will cause what?

ipsilateral trapezius weakness and ipsilateral SCM weakness. This will present in clinic as weakness of the ipsilateral trapezius and trouble turning the head to the opposite side of the SCM weakness


UMN leasion of CN XI will cause

contralateral trapezius weakness and ipsilateral weakness of the SCM (on the side of the UMN lesion)


Why does the SCM receive ipsilateral innervation from UMN

To insure that your head turns to the side that you are catching the ball. If you are catching a ball with your left hand, you need the SCM on your right side to work.


CN XII leaves the skull via what foramen



CN XII controls

tongue movement


Unilateral lesions of CN XII or its nuclei produce what

tongue sticks out towards the side of the lesion (b/c contraction of the left side pushes it toward the right and vice cersa)


Unilateral lesions of CN XII UMN cause

tongue to deviate away from lesion