-
Olfactory Nerve ( CN I) Lesion?
- -Loss of smell (anosmia)
- -Loss affects taste
- - Could result from trauma involving cribiform plate of ethmoid bone
- -Chronic exposure to lead, chlorine, and cadmium
-
Optic Nerve (CN II)
- -Passes through Optic canal
- -Crosses at optic chiasm
- -Inflammation of infundibulum can compress nerve
-
Oculomoter Nerve (CNIII)
- -muscle efferent to extrinsic eye muscles
- -medial rectus
- -superior rectus
- -inferior rectus
- -inferior oblique
- -Muscle efferent to upper eyelid
- -levator palpebrae superioris muscle
- -Eye closes with lesion
- -ptosis
-
Oculomoter Nerve parasympathetics?
- - postganglionics to intrinsic eye muscles from ciliary ganglion
- -constrictor pupillae muscle
- - ciliary muscle - controls lens thickness
-
Sympathetics of the intrinsic eye?
- - enters orbit with carotid plexus
- -Dilator pupillae muscle
- -Muller's muscle (superior tarsal muscle)
- -smooth muscle
-
Where does oculomotor nerve arise from?
- oculomotor nuclear complex of the midbrane
- -leaves the brainstem in the interpeduncular fossa
- -enters orbit through superior orbital fissure
-
What two arteries does the oculomotor nerve pass between?
superior cerebellar and posterior cerebral arteries
-
Two branches of oculomotor nerve (CN III)
- -superior
- -levator palpebrae superioris
- -superior rectus
- -inferior
- -inferior and medial rectus
- -inferior oblique
- -cilliary ganglion
-
3rd nerve palsy, injury to oculomotor nerve?
- -eye looks down and away
- -unopposed action of the lateral rectus and superior oblique
- -eyelid closed
- -fixed dilated pupil
- -unopposed sympathetics
-
Trochlear Nerve (IV)
- -muscle efferent
- -from dorsal aspect of the mesencephalon (midbrane)
- - innervantes superior oblique
- -superior orbital fissue
- -pulls eye down
-
CN IV Leasion
- -sever head trauma
- -diplopia (double vision)
- -tilts head down and away from affected side
-
Trigeminal Nerve (V)
- -sensory afferent pg 695 in book
- -Efferent (muscles from first branchial arch)
- -muscles of mastication
- -tensor tympani
- tensor velli palantini
- -anterior belly of digastric muscle
- -mylohyoid muscle
-
Trigeminal Divisions all sensory
- V1 opthalmic - cornea and nasal cavity
- V2 maxillary- maxillary teeth, sinuses
- V3 mandibular - anterior 2/3 tongue, touch sense
-
Trigeminal Neuralgia AKA tic douloureux
- -most common cranial neuralgia
- -attacks of excruciating pain over the nerve branches
- -mostly V2 and V3
- -treat with antiepileptic drugs
-
Abducens Nerve (CN VI)
- - sensory and motor
- - lateral rectus
- -exits bran stem at the pontomedullary junction
- -enters through superior orbital fissure
-
Abducens Nerve Lesion?
- Vlth Nerve palsy
- -Lateral Gaze defect
-
Fascial Nerve (CNVII)
- -Motor to muscles of fascial expression
- -derived from second branchial arch
- -also stapedius muscle. posterior belly of digastric muscle
- -Taste anterior 2/3 tongue via chorda tympani
- -Viscral preganglionic efferents arise in the superior saslvatory nucleus
- -travels through the paratid gland
-
Facial nerve branches?
- -Temporal
- -Zygomatic
- -Buccal
- -Mandibular
- -Cervical
-
Attenuation Reflex?
after exposure to loud sound the stapedius and tensor tympani contract to protect ear.
-
Bells Palsy?
- -most common fascial nerve disorder
- -spontaneous onset
- -gradual recovery
- - always idiopathic. not from trauma
-
Vestibulocochlear Nerve (CN VIII)
- -vestibular nerve-balance, head position and movement
- -cochlear nerve - hearing
- through internal auditory meat
-
Acoustic Neuroma?
- -Acoustic schwannoma
- -cerebellopontine angle
- -slow growth
- -benign but space occupying
- -Tinnitus (ringing in ears), hearing loss and vertigo
- -can also compress fascial nerve and cause facial paralysis
-
Glossopharyngeal Nerve CN(IX)
- -posterior 1/3 of tongue taste
- -sensation of posterior 1/3 pf tongue
- -motor to stylopharygeus muscle
- - from carotid body, pharynx, middle ear ( gag reflex)
- -pre ganglionic to otic ganglion then to parotid gland
-
Vegus Nerve X
- -Taste, epiglottis and palate
- -sensation from tongue, pharynx, trachea, heart , foregut, and midgut
- -motor to constrictor muscle of pharynx, intrinsic muscles of larynx, muscles of palate
- -sensory from external auditory meatus, dura of posterior fossa
- -visceral efferent to gut
-
Injury to Vegus nerve
- -Uvula will deviate to the opposite side, Normal side
- -palatoglossus muscle will not contract on affected side
- -curtain call
-
Accessory Nerve (XI)
- -motor to striated muscle of soft palate, pharynx and larynx via fibers joined with X
- -motor to SCM and trapezius
-
Hypoglossal Nerve (CN XII)
- -motor only to muscles of the tongue except the palatoglossus
- -No sensory
-
Injury to CN XII
-protruded tongue points toward side of damage.
|
|
