FACIAL NERVE
NEUROANATOMY
C J ABDUL KALAM
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? Facial nerve is the nerve of second branchial arch? It's a mixed nerve, contains motor , sensory & autonomic fibres
? Motor ? muscles of facial expression , platysma ,post belly of
digastric , stylohyoid
? Sensory ?taste sensation from anterior 2\3rd of tongue , smal area
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around concha of ear? Autonomic ? lacrimal , sublingual & submaxil ary glands
NUCLEI
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? All four nuclei lie in lower pons1. Motor nucleus/branchiomotor
2. Superior salivary nucleus
3. Lacrimatory nucleus
4. Nucleus of tractus solitarius
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FUNCTIONAL COMPONENTS
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? Special visceral /branchial efferent muscles? General visceral efferent salivary glands , palatal , nasal &
pharyngeal glands
? General visceral afferent afferent impulse from above glands
? Special visceral afferent ant 2/3rd of tongue, soft palate
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? General somatic afferent skin of ear--- Content provided by FirstRanker.com ---
COURSE OF FACIAL NERVE
INTRACRANIAL PART
? Attached to brainstem by two roots motor & sensory( nerve of
Wrisberg ) at the lower border of pons medial to eight nerve in
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the cerebellopontine angle? 15 ? 17 mm in length
? It reach internal acoustic meatus along with vestibulocochlear nerve
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INTRA TEMPORAL PART? MEATAL SEGMENT(15 ? 17 mm)
? LABRYNTHINE SEGMENT( 4 mm)
? Narrowest segment & thin bony canal
? First genu
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? TYMPANIC / HORIZONDAL SEGMENT ( 11 mm)? From geniculate ganglion to pyramidal eminence
? Above oval window & below lateral semi-circular canal
? MASTOID/VERTICAL SEGMENT (13 mm)
? Pyramid to stylomastoid foramen
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? Second genu lies between mastoid & tympanic segmentEXTRACRANIAL PART
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BRANCHES
? Greater superficial petrosal nerve
? Arises from geniculate ganglion & carries secretomotor fibres to lacrimal gland &
gland of nasal mucosa & palate
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? Nerve to stapedius? Arises from second genu & supplies stapedius
? Corda tympani
? Arises from vertical segment , passes between incus & stapes ,leaves tympanic
cavity through petro tympanic fissure, supplies to submandibular , sublingual ,
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brings taste from ant 2/3rd of tounge? Communicating branch
? Joins auricular branch of vagus & supplies concha ,outer surface of tympanic
membrane, posterior meatus
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? Posterior auricular nerve? Supplies muscles of pinna , occipital belly of occipitofrontalis ,communicates
with auricular branch of Vagus
? Muscular branches
? Stylohyoid ,posterior belly of digastric
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? Peripheral branches? Upper temporofacial
? Lower cervicofacial
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? Peripheral branches ( pes anserinus )? Temporofacial
? Temporal
? Auricularis anterior
? Auricularis superior
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? Frontalis? Orbicularis oculi
? Corrugator supercilia
? Zygomatic
? Orbicularis oculi
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? Cervicofacial
? Buccal
? Two branches ? upper & lower buccal ,supplies muscles in vicinity mainly
buccinator
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? Marginal mandibular? Muscles of lower lip ? orbicularis oris , mentalis ,depressor labi anguli etc
? Cervical
? Platysma
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