The facial nerve is the 7th cranial nerve that innervates the muscles of facial expression. It has motor, sensory, and parasympathetic components. The facial nerve emerges from the skull through the stylomastoid foramen and divides into 5 terminal branches that innervate various facial muscles. Within the facial canal, it gives off branches like the chorda tympani nerve. Facial nerve injury can cause upper or lower motor neuron lesions with corresponding symptoms.

1. FACIAL NERVE

2. • IT IS 7TH CRANIAL NERVE
• KNOWN AS QUEEN OF FACE
• NERVE OF 2ND BRANCHIAL ARCH

3. FUNCTIONAL COMPONENTS
1. SPECIAL VISCERAL EFFERENT:MUSCLES OF
FACIAL EXPRESSION,ELEVATION OF HYOID
BONE
2. GENERAL VISCERAL
EFFERENT:SECRETOMOTOR TO
SUBMANDIBULAR ,SUBLINGUAL
GLAND,LACRIMAL GLAND,GLAND OF
NOSE,PALATE,PHARYNX
3. GENERAL VISCERAL AFFERENT

4. • SPECIAL VISCERAL AFFERENT:CARRY TASTE
SENSATION TO ANT2/3RD OF TONGUE EXCEPT
VALATE PAPILLA
• GENERAL SOMATIC AFFERENT:SKIN OF EAR

5. NUCLEI
• 4 NUCLEI IN LOWER PONS
1. MOTOR OR BRANCHIOMOTOR
2. SUPERIOR SALIVATORY
3. LACRIMAL
4. NUCLEUS TRACTUS SOLITARIUS
MOTOR ROOT LIES IN DEEP IN RETICULAR
FORMATION OF PONS

6. COURSE
• ATTACH TO BRAIN STEM AT OR CLOSE TO JUNCTION
OF PONS WITH MEDULLA
• ATTACHED TO BRAIN STEM BY 2 ROOTS
• MOTOR
• SENSORY
• SENSORY –NERVOUS INTERMEDIUS
• 2 ROOTS OF FN ARE ATTACHED TO LOWER BORDER
OF PONS JUST MEDIAL TO 8TH NERVE

7. • 2 ROOTS RUN LATERALLY AND FORWARD
WITH 8TH CN TO REACH INTERNAL ACOUSTIC
MEATUS
• IN MEATUS MOTOR ROOT LIES IN A GROOVE
WITH 8TH ERVE WITH SENSORY ROOT
INTERVEANING
• 7TH &8TH NERVE ARE ACCOMPANIED BY
LABRYNTHINE VESSEL
• AT BOTH OR FUNDUS OF MEATUS 2 ROOTS IE
SENSORY & MOTOR FUSES TOGETHER &
FORM SINGLE TRUNK WHICH LIES IN PART OF
PETROUS 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 DOWN
POSTERIOR WALL OF TYMPANIC CAVITY TO
STYLOMASTOID FORAMEN
• WITHIN CANAL IT DIVIDES IN TO 3 PART WITH 2
BENDS
• 1ST PART IS DIRECTED LATERALLY ABOVE
VESTIBULE
• 1ST BEND-AT JUNCTION OF 1ST & 2ND PART WHICH
IS SHARP
• LIES OVER ANTERIOR SUPERIOR PART
PROMONTRY

9. • IT IS CALLED AS GENU
• HERE GENICULATE GANGLION LIES
• BRANCHES WHICH ARISES FROM FN WITHIN
TEMPORAL BONE CAN BE DIVIDED IN TO
THOSE WHICH COMES FROM GENICULATE
GANGLION
• 2ND PART RUNS BACKWARD IN RELATION TO
MEDIAL WALL OR MIDDLE EAR OF
PROMONTORY
• 2ND BEND IS GRADUAL AND LIES IN B/W
PROMONTORY & ADITUS TO MASTOID
ANTRUM

10. • 3RD PART DIRECTED VERTICALLY DOWNWARD
BEHIND PROMONTORY
• MAIN BRANCH FROM GANGLION IS “GREATER
PETROSAL NERVE”
• A BRANCH OF NERVOUS INTERMEDIOUS
• PASS ANTERIORLY
• RECIEVES BRANCH FROM TYMPANIC PLEXUS
AND TRAVERSOUS A HIATUS ON ANTERION
SURFACE OF PETROUS PART OF TEMPORAL
BONE
• ENTER MIDDLE CRANIAL FOSSA

11. • RUNS FORWARD IN GROOVE ON BONE ABOVE
LESSER PETROSAL NERVE
• PASSES BENEATH TRIGEMINAL GANGLION TO
REACH FORAMEN LACERUM
• VIDINOUS NERVE
• EXTRACRANIAL COURSE
• FN EMERGES FROM BASE OF SKULLAT
STYLOMASTOID FORAMEN
• LIES 9MM AWAY FROM POST BELLY OF
DIGASTRIC & 11MM FROM BONY EXTERNAL
ACOUSTIC MEATUS

12. • MAINLY MOTOR SUPPLY IT ALSO ACCOMPANY
AURICULAR BRANCH OF VAGUS
• INNEVATE ON BOTH AURICLE ASPECT
CONCHAL DEPRESSION
OVER ITS EMINANCE
• CLOSE TO STYLOMASTOID FORAMEN FN GIVES
OFF POSTERIOR AURICULAR NERVE WHICH
SUPPLIES OCCIPITAL BELLEY OF
OCCIPITOFRONTALIS,AURICULAR
MUSCLE,POST BELLEY OF
DIGASTRIC,STYLOHYOID

13. • ENTER PAROTID GLAND FROM
POSTEROMEDIAL SURFACE AND PASS
FORWARD AND DOWNWARD BEHIND
MANDIBULAE RAMUS
• GIVES OFF TEMPEROFACIAL & CERVICOFACIAL
TRUNK
• LIES SUPERFICIAL TO RETRO MANDIBULAR
VEIN
• TRUNK BRANCHES TO FORM A PAROTID
PLEXUS “PES ANSERINUS”
• 5 TERMINAL BRANCH

14. BRANCHES
A. WITHIN FACIAL CANAL
• GREATER PETROSAL NERVE
• NERVE TO STAPEDIOUS
• CHORDAE TYMPANI
B.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 CANAL
ABOUT 6MM ABOVE STYLOMASTOID
FORAMEN
• RUNS UPWARD AND FORWARD IN BONY
CANAL
• ENTERS MIDDLE EAR & RUNS FORWARD IN
CLOSE 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 GLAND
ANTERIOR 2/3RD OF TONGUE

18. 5 TERMINAL BRANCHES
1. TEMPORAL:
A)FRONTALIS
B)ORBICULARIS OCCULI
C)COROGATOR SUPERCILII
2.ZYGOMATIC:
A)ORBICULARIS OCCULI

19. 3.BUCCAL:
A)LAVETOR ANGULI ORIS
B)ZYGOMATICUS MINOR
C)LAVETOR LABI SUPERIORIS ALAQUE
NASI
D)SMALL NASAL MUSCLE
E)PROCERUS
F)BUCCINATOR
G)ORBICULARIS ORIS

20. 4.MARGINAL MANDIBULAR:
A)RISORIUS
B)MUSCLE OF LOWER LIP & CHIN
C)JOIN MENTAL NERVE
5.CERVICAL:
A)PLATYSMA

21. FACIAL NERVE INJURY
• UMN LESION: