FACIAL NERVE

Facial nerve

1. FACIAL NERVE
2. • IT IS 7TH CRANIAL NERVE• KNOWN AS QUEEN OF FACE• NERVE OF 2ND BRANCHIAL ARCH
3. FUNCTIONAL COMPONENTS1. SPECIAL VISCERAL EFFERENT:MUSCLES OFFACIAL EXPRESSION,ELEVATION OF HYOIDBONE2. GENERAL VISCERALEFFERENT:SECRETOMOTOR TOSUBMANDIBULAR ,SUBLINGUALGLAND,LACRIMAL GLAND,GLAND OFNOSE,PALATE,PHARYNX3. GENERAL VISCERAL AFFERENT
4. • SPECIAL VISCERAL AFFERENT:CARRY TASTESENSATION TO ANT2/3RD OF TONGUE EXCEPTVALATE PAPILLA• GENERAL SOMATIC AFFERENT:SKIN OF EAR
5. NUCLEI• 4 NUCLEI IN LOWER PONS1. MOTOR OR BRANCHIOMOTOR2. SUPERIOR SALIVATORY3. LACRIMAL4. NUCLEUS TRACTUS SOLITARIUSMOTOR ROOT LIES IN DEEP IN RETICULARFORMATION OF PONS
6. COURSE• ATTACH TO BRAIN STEM AT OR CLOSE TO JUNCTIONOF PONS WITH MEDULLA• ATTACHED TO BRAIN STEM BY 2 ROOTS• MOTOR• SENSORY• SENSORY –NERVOUS INTERMEDIUS• 2 ROOTS OF FN ARE ATTACHED TO LOWER BORDEROF PONS JUST MEDIAL TO 8TH NERVE
7. • 2 ROOTS RUN LATERALLY AND FORWARDWITH 8TH CN TO REACH INTERNAL ACOUSTICMEATUS• IN MEATUS MOTOR ROOT LIES IN A GROOVEWITH 8TH ERVE WITH SENSORY ROOTINTERVEANING• 7TH &8TH NERVE ARE ACCOMPANIED BYLABRYNTHINE VESSEL• AT BOTH OR FUNDUS OF MEATUS 2 ROOTS IESENSORY & MOTOR FUSES TOGETHER &FORM SINGLE TRUNK WHICH LIES IN PART OFPETROUS PART OF TEMPORAL BONE
8. • MOTOR ROOT SUPPLIES MUSCLE OF FACE• NERVOUS INTERMEDIUS –TASTE PERCEPTION• ENTERS ITS OWN CANAL IE FACAIL CANAL• RUNS ACROSS MEDIAL WALL AND DOWNPOSTERIOR WALL OF TYMPANIC CAVITY TOSTYLOMASTOID FORAMEN• WITHIN CANAL IT DIVIDES IN TO 3 PART WITH 2BENDS• 1ST PART IS DIRECTED LATERALLY ABOVEVESTIBULE• 1ST BEND-AT JUNCTION OF 1ST & 2ND PART WHICHIS SHARP• LIES OVER ANTERIOR SUPERIOR PARTPROMONTRY
9. • IT IS CALLED AS GENU• HERE GENICULATE GANGLION LIES• BRANCHES WHICH ARISES FROM FN WITHINTEMPORAL BONE CAN BE DIVIDED IN TOTHOSE WHICH COMES FROM GENICULATEGANGLION• 2ND PART RUNS BACKWARD IN RELATION TOMEDIAL WALL OR MIDDLE EAR OFPROMONTORY• 2ND BEND IS GRADUAL AND LIES IN B/WPROMONTORY & ADITUS TO MASTOIDANTRUM
10. • 3RD PART DIRECTED VERTICALLY DOWNWARDBEHIND PROMONTORY• MAIN BRANCH FROM GANGLION IS “GREATERPETROSAL NERVE”• A BRANCH OF NERVOUS INTERMEDIOUS• PASS ANTERIORLY• RECIEVES BRANCH FROM TYMPANIC PLEXUSAND TRAVERSOUS A HIATUS ON ANTERIONSURFACE OF PETROUS PART OF TEMPORALBONE• ENTER MIDDLE CRANIAL FOSSA
11. • RUNS FORWARD IN GROOVE ON BONE ABOVELESSER PETROSAL NERVE• PASSES BENEATH TRIGEMINAL GANGLION TOREACH FORAMEN LACERUM• VIDINOUS NERVE• EXTRACRANIAL COURSE• FN EMERGES FROM BASE OF SKULLATSTYLOMASTOID FORAMEN• LIES 9MM AWAY FROM POST BELLY OFDIGASTRIC & 11MM FROM BONY EXTERNALACOUSTIC MEATUS
12. • MAINLY MOTOR SUPPLY IT ALSO ACCOMPANYAURICULAR BRANCH OF VAGUS• INNEVATE ON BOTH AURICLE ASPECTCONCHAL DEPRESSIONOVER ITS EMINANCE• CLOSE TO STYLOMASTOID FORAMEN FN GIVESOFF POSTERIOR AURICULAR NERVE WHICHSUPPLIES OCCIPITAL BELLEY OFOCCIPITOFRONTALIS,AURICULARMUSCLE,POST BELLEY OFDIGASTRIC,STYLOHYOID
13. • ENTER PAROTID GLAND FROMPOSTEROMEDIAL SURFACE AND PASSFORWARD AND DOWNWARD BEHINDMANDIBULAE RAMUS• GIVES OFF TEMPEROFACIAL & CERVICOFACIALTRUNK• LIES SUPERFICIAL TO RETRO MANDIBULARVEIN• TRUNK BRANCHES TO FORM A PAROTIDPLEXUS “PES ANSERINUS”• 5 TERMINAL BRANCH
14. BRANCHESA. WITHIN FACIAL CANAL• GREATER PETROSAL NERVE• NERVE TO STAPEDIOUS• CHORDAE TYMPANIB.AS IT EXISTS STYLOMASTOID FORAMEN• POSTERIOR AURICULAR• DIGASTRIC• STYLOHYOID
15. C.TERMINAL BRANCHES• TEMPORAL• ZYGOMATIC• BUCCAL• MARGINAL MANDIBULAR• CERVICAL
16. CHORDAE TYMPANI• ARISE IN VERTICAL PART OF FACIAL CANALABOUT 6MM ABOVE STYLOMASTOIDFORAMEN• RUNS UPWARD AND FORWARD IN BONYCANAL• ENTERS MIDDLE EAR & RUNS FORWARD INCLOSE RELATION TO TYMPANIC MEMBRANE• LEAVES MIDDLE EAR
17. • VIA PETROTYMPANIC FISSURE• MEDIAL TO SPHENOIDAL SPINE• ENTERS INFRA TEMPORAL FOSSA• JOIN LINGUAL NERVE• SUPPLIES:SUB MANDI,SUB LINGUAL GLANDANTERIOR 2/3RD OF TONGUE
18. 5 TERMINAL BRANCHES1. TEMPORAL:A)FRONTALISB)ORBICULARIS OCCULIC)COROGATOR SUPERCILII2.ZYGOMATIC:A)ORBICULARIS OCCULI
19. 3.BUCCAL:A)LAVETOR ANGULI ORISB)ZYGOMATICUS MINORC)LAVETOR LABI SUPERIORIS ALAQUENASID)SMALL NASAL MUSCLEE)PROCERUSF)BUCCINATORG)ORBICULARIS ORIS
20. 4.MARGINAL MANDIBULAR:A)RISORIUSB)MUSCLE OF LOWER LIP & CHINC)JOIN MENTAL NERVE5.CERVICAL:A)PLATYSMA
21. FACIAL NERVE INJURY• UMN LESION: