cranial nerves 2 Flashcards
whats the names of the three trigeminal motor nerve roots
opthalmic, maxillary, mandibular
where do each of the trigeminal motor nerve roots supply
opthalmic being the eyes, forehead, top of head and cornea
maxillary being the maxillary bone area
mandibular being the mandibular region
where are the cell bodies of the trigeminal motor nerves
in the trigeminal ganglion
which trigeminal nerve also carries motor function and what is that motor function to
carring motor function is the mandibular branch of the trigeminal nerve. carrying it to the muscles of mastication and tensor tympani
what muscles does the trigeminal nerve innervate
tensor tympani, The lateral pterygoid, medial pterygoid, temporalis and masseter muscles. And muscles of the floor of the mouth
what do we see in lesions of the trigeminal motor nerve
UMN one side of chewing will be a bit weaker due to the bilateral UMN innervation but not too bad.
LMN will have mouth deviated to the affected side when open. as the still functioning lateral pterygoid makes jaw go to other side. so ipsilateral weakness
what is the sensory functions of the facial nerve
carries light touch from the concha, back of the ear, external acoustic meatus, outside of the tympanic membrane
what path does the sensory aspect of the facial nerve follow
along the auricular branch of the vagus nerve with its cell body in the geniculate ganglion. then axon going through the internal acoustic meatus to the brainstem via the nervus intermedius to the STNC at the pontine level. as light touch
what is the motor function of the facial nerve
to the muscles of facial expression. superficial neck muscles, swallowing and muscles of floor of mouth
how do we test function of the sensory trigeminal nerve
touch their face with cotton bud and sharp thing on both sides of the sensory area and the ear. and do the eye
how do we test function of the facial motor nerves
get them to furrow brow, puff cheeks, smile, close their eyes tight and we try open them
whats the path the facial nerve takes for motor functions
cell body in facial nucleus, then goes through the geniculate ganglion with no synapse. then through internal acoustic meatus, then goes to stapedius muscle.
otherwise it will then head through stylomastoid foramen through the parotid gland but does nothing there. then to the muscles of facial expression and what not
what happens when UMN and LMN lesion of the facial nerve
UMN we get the lower face weakness on the opposite side as the top part of face is bilaterally innervated but lower is only contralateral
LMN gets ipsilateral whole side weakness
what does the glossopharyngeal nerve carry
sensation from the back of the throat and uvula - gag reflex
taste from posterior 1/3 of the tongue
visceral sensation from post 1/3 tongue, upper pharynx, middle ear, eustachian tube
what ganglion does the glossopharyngeal nerve have
superior glossopharyngeal ganglion for all but taste
inferior glossopharyngeal ganglion gets taste
functions of the vagus nerve somatic sensory wise
pain and temperature for the external parts of the ear.
functions of the vagus nerve visceral sensation wise
- Vagus and cranial root 11 has baroreceptors In the aortic arch, chemoreceptors in the aortic body, lung stretch receptors, mucus membrane receptors in airways, gut stretch receptors and gut chemoreceptors.
visceral motor functions of the vagus nerve
this is the vagus being the PNS supply for like most things.
The postganglionics from the vagus go to plexuses of the alimentary canal, the pancreas, the stomach gastric glands, the lungs bronchial smooth muscle.
whats the functions of the vagus nerve branchial motor wise
- Vagus 10 and cranial root of the accessory 11 carry innervation to the levator palatini, muscles of the pharynx, muscles of the larynx, striated muscles of the oesophagus and the Preganglionics from the heart
○ It is thus through this nerve we have the ability to be slowing down the heart via the PNS.
functions of the hypoglossal nerve
pokes the tongue out, purely somatic motor function
motor functions of the occulomotor, trochlear and abducens nucleus
trochlear is the superior oblique
abducens is the lateral rectus
occulomotor is medial, superior, inferior recti then the inferior oblique plus the levator palpebrae superioris
whats each one of muscles innervated by the 3,4,6 do
trochlear - superior oblique - moving eye downwards when eye is adducted
abducens - lateral rectus - move eye laterally
occulomotor - medial rectus - eye medially - superior rectus - eye up - inferior rectus - eye down - inferior oblique - eye upwards when adducted
what do we do when we want to test the 3,4,6
get them to look in all directions eye can
what happens when the abducens nerve is lesioned
the lateral rectus cannot function so eye cant be moved laterally and at rest will have slight medial pull
what happens when the trochlear nerve is lesioned
superior oblique cant function. the patient cant move eye downwards when in an adducted position as much as should. will get slight but thats cause of partial inferior rectus activity
what happens when we have lesioned occulomotor nerve
so most of the eye movers are damaged so we get a fixed in position pupil
the PNS innervation from the Edinger-westphal nucleus is lost so the pupil is dilated
and there is a ptosis as the eyelid is slightly closed due to levator palpabrae not working
