Spinal Nerves, Dermatomes, and Cranial Nerves Handout for Cranial Nerves.
Brief summary of Cranial Nerves: function and course
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7/28/2019 Brief summary of Cranial Nerves: function and course http://slidepdf.com/reader/full/brief-summary-of-cranial-nerves-function-and-course 1/3 CRANIAL NERVES- a summary Number- name Supplies Segments/ where? Kind of signals transmitted Presentatio n of deficit Function(s) CN1- olfactory Nasal mucosa -Does not pass through thalamus -Passes directly through cribriform plate to synapse on olfactory bulb -Cell bodies in nasal muscosa Special viscerosenso ry Anosmia/hyp erosmia/paro smia/cacosm ia (awareness of odour that does not exist) Smell CN2- optic Retina Cell bodies in ganglion cells of retina Special sensory - loss of vision ._. - visual field defects - scotomata - Mediates afferent limb of pupillary light reflex - Transmits light signals to visual cortex CN3- oculomotor Sphincter pupillae, ciliary m. Visceral motor - ptosis - dilated pupil, unreactive to pupillary light reflex (paralysis of all extraocular m.) - Mediates accomodatio n (parasym) - Mediates efferent limb of pupillary light reflex (parasym) CN4- trochlear Superior oblique Somatic motor - elevation of eye at rest, increased with head tilting towards affected side - diplopia Supplies superior oblique muscle CN5- trigeminal 'Face mask' V1- forehead, eyelid, conjunctiva, cornea, dura, V2- cheeks, nasal cavity, upper jaw V3- lower jaw, ant 2/3 of tongue, ext auditory meatus TRIgeminal so THREE divisions: V1- opthalmic V2- maxillary V3- mandibular (with motor component) Somatic sensory Somatic motor - jaw jerk reflex (!) - tic douloureux/tr igeminal neuralgia- paroxysmal extreme pain, oft b/c trigger e.g. chewing - corneal dryness/abra sion Mastication Som sen in face CN6- abducens Lateral rectus Motor - eye looks medially b/c unopposed medial rectus (failure to Supplies lateral rectus
Transcript of Brief summary of Cranial Nerves: function and course
7/28/2019 Brief summary of Cranial Nerves: function and course
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CRANIAL NERVES- a summary
Number-name
SuppliesSegments/where?
Kind of signalstransmitted
Presentation of deficit
Function(s)
CN1-olfactory
Nasalmucosa
-Does notpass
throughthalamus-Passesdirectlythroughcribriformplate tosynapse onolfactorybulb-Cell bodiesin nasalmuscosa
Specialviscerosensory
Anosmia/hyperosmia/parosmia/cacosmia(awarenessof odour thatdoes notexist)
Smell
CN2- optic RetinaCell bodies inganglioncells of retina
Specialsensory
- loss of vision ._.- visual fielddefects- scotomata
- Mediates
afferent limbof pupillarylight reflex- Transmitslight signalsto visualcortex
CN3-oculomotor
Sphincterpupillae,ciliary m.
Visceralmotor
- ptosis- dilatedpupil,unreactive topupillarylight reflex(paralysis of
allextraocularm.)
- Mediatesaccomodation (parasym)- Mediatesefferent limbof pupillary
light reflex(parasym)
CN4-trochlear
Superioroblique
Somaticmotor
- elevation of eye at rest,increasedwith headtiltingtowardsaffected side- diplopia
Suppliessuperiorobliquemuscle
CN5-trigeminal
'Face mask'V1- forehead,eyelid,conjunctiva,cornea, dura,V2- cheeks,nasal cavity,upper jawV3- lower
jaw, ant 2/3of tongue,ext auditorymeatus
TRIgeminal
so THREEdivisions:V1-opthalmicV2- maxillaryV3-mandibular(with motorcomponent)
SomaticsensorySomaticmotor
- jaw jerkreflex (!)- tic
douloureux/trigeminalneuralgia-paroxysmalextremepain, oft b/ctrigger e.g.chewing- cornealdryness/abrasion
MasticationSom sen inface
CN6-abducens
Lateralrectus
Motor - eye looksmedially b/cunopposed
medialrectus(failure to
Supplieslateral rectus
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abduct)- diplopiaexceptduring lateralgaze towardsunaffectedside
CN7- facial'Slap frombehind'
Terminalbranches:zygomatic,buccal,cervical,marginalmandibular
SomaticmotorVisceralmotor(glands)Somaticsensory(facialexpressions)Specialsensory
(taste)
LMN lesion-Bell's palsy -ipsilateralparalysis,loss of toneof facial m:saggymouth,evertedlower eyelid- Alteredsense of
taste
* Suppliesoccipitofrontalis,orbicularisoculi- Som sen-facialexpressions :D- VM- glands(e.g.salivary,lacrimal)- Spec sen-
taste fromant 1/2 of tongue
CN8-vestibulococchlear
Cochlea,vestibularsystem
Specialsensory(balance=special too)
- Positionalvertigo,nystagmus,motionsickness- Hearingloss/deafness- Tinnitus
Balance andhearing
CN9-
glossopharyngeal
Special
sensoryVisceralsensory
- Dysphagia,dysarthria
- Taste onpost 1/3 of tongue
- sense BPand blood O2@ carotidsinus
CN10- vagus("wandering")
Heart, respi,pharynx,larynx, GIT,palate,epiglottis
VisceralmotorSomaticmotor
- Dysphagia,dysarthria- Aphonia(hoarse/weakvoice)Bilaterallesion isincompatiblewith Life.*
- Som mot-swallowing(soft palatem., pharynx,larynx)- Somesensory?
CN11-accessory(dunno)
Cell bodies inC1-6 spinalsegments
Somaticmotor
- Ipsilateralshoulderdroop- Weaknessin turninghead tocontralateralside
Shake yourhead andshrug
CN12-hypoglossal
Supplies thetongue
Emergesfromhypoglossalnucleus
Somaticmotor
- LMN-tonguedeviatessame side aslesion- UMN-tongue
deviates toside opposite
Protrude,depress, curltonguebackward
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lesion-Dysarthria/dysphagia
✓ NB "are cranial nerves with autonomic fibres sympathetic or parasympathetic??" "THEYARE PARASYM, BECAUSE IT'S CRANIOSACRAL OUTFLOW."
✓ NB After TBI, injuries to III, IV and/or V common together✓ wrt eye muscles: SO4 LR6 All others 3* but heart can still regulate itself to a certain extent, b/c adrenaline which is sympathetic
http://calder.med.miami.edu/pointis/tbiprov/MEDICINE/sense1.htm
