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1. Anatomy of Facial Nerve
1

2. Table of contents
2
• Introduction
• Surface marking
• Functional components
• Nuclei
• Course and relations
• Branchesand distribution
• Ganglia
• Clinical anatomy

3. Introduction
3
• Seventh cranial nerve
• 2ndonly to vagus as the “busiest” cranial nerve of
the human body
• Nerve of the second branchial arch
• The facial nerve consists of the facial nerve
proper and the intermedius nerve.
• Both the facial nerve proper and the intermedius
nerve emerge from the CNS in the
cerebellopontine angle at the caudal border of
the pons, between the abducens nerve and the
vestibulocochlear nerve .

4. Surface markings
• Marked by a short
horizontal line which
joins following two
points:
1)A point at the middle
of the anterior border
of the mastoid process.
2)Behind the neck of the
mandible.
4

5. Functional components
5
impulses from the above mentioned glands.
1. Special visceral or branchial efferent, to
muscles responsible for facial expression,
posterior belly of digastric muscle , stylohyoid
and stapedius
2. General visceral efferent or
parasympathetic:
These fibers are secretomotor to the
submandibular and sublingual salivary glands,
the lacrimal gland, and glands of the nose,
the palate and the pharynx.
3. General visceral afferent : carries afferent

6. 4. Special visceral afferent fibres carry taste sensations
from the anterior two thirds of the tongue except
from vallate papillae and from the palate.
5. General somatic afferent fibres innervate a part of
skin of the ear .
Brachial motor- largest portion
6

7. Functional components of facial nerve
7

8. Nuclei
8
• The fibres of the nerve arise from four nuclei
situated in the lower pons.
1.Motor nucleus or brachiomotor : lies deep in
the reticular formation of the lower pons.
2.Superior salivatory nucleus or
parasympathetic.
3.Lacrimatory nucleus – parasympathetic.
4.Nucleus of tractus solitarius – gustatory and
also receives afferent fibres from the glands.

9. Supranuclear
anatomy
•Cortex and internal capsule:
Voluntary responses of the facial
muscles arises from efferent
discharge from motor face area
of the cerebral cortex.
•The motor face area is situated
on the pre central and post central
gyrus.
9

10. •Discharges from the facial motor
area are carried through fascicles
of the corticobulbar tract to the
internal capsule, then through the
upper midbrain to the lower
brainstem, where they synapse in
the facial nerve nucleus located in
pons.
•Corticobulbar tracts arising from
the cortical representation
of the upper face area cross and
recross in reaching the pontine
facial motor nucleus
The tracts to lower face are
crossed only once.
Posterior view of the brainstem
10

11. •Facial nerve emerges from
the brainstem with nervus
intermedius
•The average distance
between
the point where the nerves
exit the brainstem and the
place where they enter the
internal auditory canal is
approximately
15.8 mm
Contents of right internal auditory canal
11

12. Intracranial course and relations
12
•
•
•
Facial nerve is attached to the brainstem by two roots
: motor and sensory ( nervus intermedius) which are
attached to the lateral part of the lower border of
pons just medial to eight cranial nerve.
The motor and sensory root runs laterally and
forwards, with the 8thnerve to reach the internal
acoustic meatus. In the meatus the motor root lies in
a groove on the 8thnerve with the sensory root
intervening.
At the bottom of the meatus , the two roots fuse to
form a single trunk which lies in the petrous temporal
bone.

13. 13
Intracranial course of facial nerve

14. Within the canal, the course of the nerve can be
divided into three parts by two bends:
1.First part is directed laterally above the vestibule.
2.Second part runs backwards in relation to the
medial wall of the middle ear, above the promontory.
3.Third part is directed vertically downwards behind
the promontory.
14

15. Intracranial course: facial nerve exits the
Cranium at the stylomastoid foramen
15

16. •
16
•
•
The first bend at the junction of first and second
part is sharp and it is called as genu.
The second bend is gradual and lies between the
promontory and the aditus to the mastoid
antrum.
Facial nerve leaves the skull by passing through
the stylomastoid foramen.

17. Extracranial course
17
• The facial nerve crosses the lateral side of the
base of the styloid process.
• It enters the posteromedial surface of the
parotid gland, runs forwards through the
gland crossing the retromandibular vein and
the external carotid artery.
• Behind the neck of the mandible it divides into
its five terminal branches which emerge along
the anterior border of parotid gland

18. Branches and distribution
18
A. Within the facial canal:
1. Greater petrosal nerve
2. The nerve to the stapedius
3. Chorda tympani
B. At its exit from the stylomastoid foramen:
1. The posterior auricular
2. Digastric
3. Stylohyoid

19. C. Terminal branches
within the parotid gland:
1.Temporal
2.Zygomatic
3.Buccal
4.Marginal mandibular
5.Cervical
D. Communicating
branches
with adjacent cranial and
Spinal nerves.
19

20. 20

21. Greater Petrosal nerve
Leaves at the genu
•
•
•
•
•
pre ganglionic parasympathetic fibers
pterygopalatine ganglion lacrimal gland
Leaves the facial canal through the hiatus, runs forwards,
downward and inward in a furrow on the anterior
surface of the pyramid of the temporal bone.
Leaves the cranial cavity through foramen lacerum after
joining the deeo petrosal nerve from the sympathetic
plexus of the internal carotid artery
Sup and deep petrosal nerves form the pterygoid or the
vidian nerve pterygopalatine ganglion
21

22. Nerve to stapedius muscle
22
• Arises opp. to the pyramid of the middle ear
• Supplies the stapedius muscle
• Stapedius muscle – dampening of excessive
vibrations of the stapes
• In paralysis- hyperacusis

23. Chorda tympani
•
•
•
Arises 6 mm above stylomastoid foramen
Contains taste fibers and preganglionic
parasympathetic secretory fibers
Enters tympanic cavity posterior wall in close
relation to tympanic membrane Leaves the middle
ear by passing though petrotympanic fissure Enters
infratemporal fossa joins lingual nerve
23

24. Posterior auricular
• Turns backwards and upwards between the
mastoid process and the auricle
• Supplies posterior auricular and occipital
muscles
Nerve to stylohyoid
• Supplies stylohyoid muscle
Digastric
• Supplies posterior belly of digastric
24

25. Terminal branches
25
• At the stylomastoid foramen, the main trunk
enters the substance of the parotid gland.
• First separation into upper and lower division
usually occurs behind the mandible.
• The upper division- temporal, zygomatic and
upper buccal
• The lower division- lower buccal, mandibular
and cervical

26. Temporal
26
•
•
•
Emerge from the parotid gland at its upper pole
slightly in front of the superficial temporal artery
Anterior temporal : frontalis, superior part of
orbicularis oculi, corrugator supercilii, procerus
Posterior temporal : anterior and superior auricular
muscles

27. Zygomatic
27
• Leave the parotid gland on its anterosuperior
border
• Crosses the body of zygomatic bone
• Supply inferior part of orbicularis oculi

28. Buccal
28
• Emerge at the anterior border of parotid
• Upper buccal: muscles of upper lip and the
muscles of the nose
• Lower buccal : buccinator and risorius
• Orbicularis oris

29. Marginal mandibular
29
• Runs parallel to lower border of the mandible
• Cross facial vein and facial artery
• Supplies muscles of lower lip (depressor anguli
oris and depressor labii inferioris) and mental
muscles

30. Cervical
30
• Leaves parotid gland at or slightly above its
inferior pole
• Runs downward and anteriorly
• Supplies platysma

31. Communicating branches
31
• Facial nerve branches exchange fibers with
sensory cutaneous branches of the trigeminal
nerve.
• Connections between facial and trigeminal
branches results in formation of small mixed
terminal nerves, which carry motor and
sensory fibers to a limited area of the face

32. Terminal motor branches of facial nerve
32

33. Most important of these connections are:
•a branch of the auriculotemporal nerve joins the
upper branch of the facial nerve
•The upper buccal branches of the facial nerve join
branches of the infratemporal nerve in the canine fossa
•The cervical branch exchanges fibers with the
transverse colli nerve of the cervical plexus.
33

34. Ganglia
34
1. The geniculate ganglion is located on the first bend of
the facial nerve in relation to the medial wall of the
middle ear. It is a sensory ganglion. The taste fibres
present in the nerve are peripheral processes of
pseudounipolar neurons present in the geniculate
ganglion.
2. The submandibular ganglion is a parasympathetic
ganglion for relay of secretomotor fibre to the
submandibular and sublingual glands.
3. The pterygopalatine ganglion is also a
parasympathetic ganglion. Secretomotor fibres
present for the lacrimal gland relay in this ganglion.

35. Vascular Supply
35
• Proximal and middle portions of the nerve via
the anterior inferior cerebellar artery and the
internal auditory artery respectively
• Further supply of middle portion of the nerve
comes from the petrosal artery via the middle
meningeal artery of the external carotid.
• Distal segment – by stylomastoid artery, also a
branch of external carotid artery

36. References
36
•
•
•
•
•
B.D. Chaurasia’s Human Anatomy- Vol 3
Sicher And Dubrul’s Oral Anatomy
RODRIGUES, Antonio de Castro et al. Anatomy of the
Facial Nerve and its Implication in the Surgical
Procedures. Int. J. Morphol. [online]. 2009, vol.27, n.1
Gulam Hasan, Ashfaqul Hasan,Kulbeer Kaur, Muzaffar
Ahmad, Mohd. Shafi, The Facial Nerve : The
Anatomical and Surgical important,JK-
Practitioner2005;12(1):53-57
Mark May , Barry M. Schaitkin The facial nerve 2nd
edition