Cranial Nerves Flashcards
what cranial nerves come off the midbrain?
3 and 4
what cranial nerves come off the pons?
5678
what cranial nerves come off the medulla
9,10,11,12
what cranial nerves have motor function?
3 4 5 6 7 9 10 11 12
what cranial nerve have somatosensory fxn?
5
7
9
10
what cranial nerves have special sensory fxn?
1 2 8 7 9 10
what cranial nerves have parasymp fxn?
3
7
9
10
where does the olfactory nerve send information in the brain? 2 locations
into the cortex and the limbic system
where does the optic nerve send information?
lateral geniculate nucleus of thalamus and then visual cortex
what are the two fxns of the occulomotor nerve?
motor and parasympathetic
what is the motor action of the occulomotor nerve?
innervation to superior, medial and inferior rectus muscles and the inferior oblique muscle of the eye
and the levator palpebrae
where is the brainstem nucleus for the occulomotor nerve motor portion?
occulomotor nucleus
where is the brainstem nucleus for the occulomotor parasympathetic portion?
edinger westphal nucleus
what is the parasympathetic fxn of the occulomotor nerve?
pupillary constriction and lens accomodation
where do the parasympathetic info from the occulomotor go to release their effects?
ciliary ganglia
if you damage C3, how does eye appear?
eyelid droop with eye looking down and out and pupillary dilation
where are the occulomotor nerve nuclei located in the midbrain?
close to the cerebral aqueduct in the dorsal portion
what vessel supplies the nuclei of the occulomotor nerve?
PCA
what is the action of the trochlear nerve?
only motor
what is the motor target of the trochlear nerve?
superior oblique of the eye
where do the nuclei of the trochlear nerve live?
in the trochlear nucleus in the midbrain
if trochlear nerve is damaged, what happens to eye?
it will pull up and in
where is the trochlear nucleus located in the midbrain?
dorsal portion close to cerebral aqueduct
what vessel serves the trochlear nucleus?
PCA
what is unique about the trochlear nerve as it leaves the trochlear nucleus?
it heads dorsally and decussates posterior to the cerebral aqueduct
where is the nuclei of the trigeminal nerve?
pons
what are the three subdivisions of the trigeminal?
opthalmic
maxillary
mandibular
what types of function does trigeminal carry?
motor and somatosensory
what does the trigeminal provide motor innervation to?
muscles of mastication
what does the trigeminal provise somatosensory to?
face, nasal/oral cavity, meninges and cornea of the eye
what part of the eye does the trigeminal nerve provide sensation to?
cornea
what is CN V palsy?
abnormal corneal reflex
weakness of muscles of mastication and loss of somatosensation
what are the two nuclei of the trigeminal nerve?
spinal trigeminal nucleus
main nucleus of trigeminal
what does the main nucleus of the trigeminal carry?
touch, vibration
what does the spinal trigeminal nucleus have?
pain/temp
where is the main nucleus of the trigeminal located?
in the lateral part of the pons
what vessel serves the main nucleus of the trigeminal?
AICA
aside from the muscles of mastication, what does the trigeminal motor nucleus provide innervation to?
tensor tympani muscle
where is the abducens nerve connected to the brainstem?
the pontomedullary junction
is the abducens nerve lateral or medial at the pontomedullary junction?
it is the most medial
what function does the abducens nerve carry?
only motor
what muscle does the abducens nerve innervate?
lateral rectus of the eye
damage to the abducens nerve leads to what physical exam sign?
when patient asked to look laterally the eye stays midline
where is the nuclei of the abducens nerve located in the pons?
medial portion
what vessel serves the abducens nuclei in the pons?
pontine
what functions does the facial nerve carry?
motor
somatosensory and
parasympathetic
what is the motor function of the facial nerve?
muscles of facial expression and stapedius muscle
what is the sensory innervation of the facial nerve?
anterior 2/3 of tongue
what is the parasympathetic function of the facial nerve?
salivary and lacrimal glands via the submandibular and pterrygopalantine ganglia
what can the motor part of the facial nerve cause with the eye?
eye lid to close
clinically what do you see with damage to facial nerve?
one side of face is paralyzed
what portion of the pons is the facial nucleus located in?
medial portion
what vessel serves the facial nucleus in the pons?
pontine
what is unique about the motor innervation of the face?
it has UMN control from the cortex
if the UMN for facial control is knocked out, what happens?
there is facial paralysis contralaterally but only on the lower half of the face
why does UMN injury of facial motor innervation only lead to lower contralateral face paralysis?
because there is ipsilateral backup for the upper face region in the cortex
what are the two nerves involved in the corneal reflex?
V for sensation
VII for motor
cranial nerve has what functions?
sensory only
what are the two nuclei of the vestibulocochlear?
cochlear nucleus
vestibular nucleus
what are the two main sensory roles of the vestibulocochlear nerve?
hearing and proprioception and balance
what are symptoms of damage to vestibulocochlear nerve>
loss of hearing, nausea and vertigo
what portion of the pons do the vestibulocochlear nuclei reside?
lateral posterior
what is the blood supply for the vestibulocochlear nuclei?
AICA
what are the functions of the glossopharyngeal nerve?
somatosensation
special sensory
parasympathetic
motot
what is the special sense that glossopharyngeal has?
sens of taste from posterior 1/3 of tongue
what is the parasympathetic activity the glossopharyngeal has?
salivary glands
what is the motor function of the glossopharyngeal nerve?
stylopharyngeus innervation
what is the somatosensory info that the glossopharyngeal carries?
from tongue and pharynx, and carotid body/sinus
what is the reflex that is involved with glossopharyngeal?
gag reflex
where is the glossopharyngeal nuclei located in the medulla?
lateral portion, outside of olives
what are the three nuclei that the glossopharyngeal uses?
spinal trigeminal nucleus
nucleus solitarius
and
ambiguus nucleus
what vessel serves the glossopharyngeal nuclei?
PICA
what are the functions of the vagus nerve?
sensory
motor
parasympathetic
what is the sensory function of the vagus?
larynx, pharynx, aortic body/arch
what is the motor function of the vagus?
soft palate, pharynx and larynx
what nerve is involved in speaking?
vagus
what nerve is in charge of swallowing?
vagus
what is the parasympathetic function of the vagus?
to respiratory, GI and CV
what are the three clinical symptoms of vagus nerve damage?
abnormal gag reflex, dysphagia and hoarseness
what are the nuclei used by the sensory portion of the vagus?
nucleus solitariu and spinal trigeminal nuclei
what is the nucleus used by vagus motor?
nucleus ambiguus
where are the nuclei of the vagus located?
lateral portion of medulla outside of olives
what vessel serves nuclei of vagus?
PICA
what functions are carried by spinal accessory?
motor to trapezius and SCM
what does spinal accessory damage lead to
weak shoulder shrug and weak head turn to opposite side of lesion
is the weakness in head turn on the same side or opposite side of lesion?
opposite side of lesion
what functions does the hypoglossal nerve carry?
motor to tongue muscles
what nuclei does the hypoglossal nerve use?
hypoglossal nuclei
where does the nuclei of the hypoglossal reside?
in the posterior portion of the medulla within the pyramid
what vessel supplies the hypoglossal nucleus?
anterior spinal
lesion to the hypoglossal nerve leads to what?
deviation of tongue to same side as lesion
how many neurons are in the ascending tract for cranial nerves?
3
what is nerve 1 in ascending tract for cranial nerves?
the cranial nerve
what is nerve 2 in the ascending tract for cranial nerves?
sensory CN nucleus nerve
what nerve in the ascending tract of cranial nerves decussates?
neuron 2
where does the second neuron in the ascending tract project for cranial nerves?
to the VPM of the thalamus
where does the 3rd neuron in the ascending tract for cranial nerves start and end?
starts in VPM of thalamus and ends in somatosensory cortex
what nuclei carry almost all of the somatosensation coming from the face
CN V
what two locations is the spinal trigeminal nucleus?
pons and medulla
what two sensations is the spinal trigeminal nucleus in charge of?
pain and temperature
what two sensations are the chief sensory nucleus of the trigeminal in charge of?
fine touch and vibration
what is the name of the descending path for cranial nerves?
corticobulbar tract
how many nerves in the corticobulbar tract?
2
where is neuron 1 in the corticbulbar tract?
precentral gyrus
what is another name for neuron 1 in corticobulbar tract?
upper motor neuron
what nerve decussates in the corticobulbar tract?
upper motor neuron
where is neuron 2 in the corticobulbar tract
cranial nerve motor nuclei to the muscle
what is neuron 2 of corticobulbar tract called?
LMN
