CN V, VII, IX, XI, XII Flashcards
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 reflex…how 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) Mylohyoid 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
hypoglossal
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
