The facial nerve emerges from the brainstem and travels through the facial canal in the temporal bone. It has motor, parasympathetic, and sensory components. The motor component innervates the muscles of facial expression. The parasympathetic component innervates salivary and lacrimal glands. The sensory component provides taste sensation to the tongue and palate. The facial nerve exits the skull through the stylomastoid foramen and divides into 5 branches that innervate muscles of the face. Lesions can occur at different points along the nerve's course, resulting in varying symptoms such as facial paralysis, loss of taste, or impaired lacrimation or salivation.

1. FACIAL NERVE AND IT’S
BRANCHES
DR. MANOJ KUMAR SINGH
1st YR PG
PHYSICAL MEDICINE AND REHABILITATION
PMCH PATNA

2. INTRODUCTION
*Develops from 2nd pharyngeal arch.
*MIXED Nerve.
*7TH CRANIAL NERVE.

3. SURFACE MARKING
Marked by a short horizontal line which joins the
following two points
• A point at the middle of the anterior border of
the mastoid process. The stylomastoid
foramen lies 2 cm deep to this point.
• A second point behind the neck of the
mandible. Here the nerve divides into its 5
branches for the facial muscles.

4. Functional Components
• Special visceral or branchial efferent, to
muscles responsible for facial expression and
for elevation of the hyoid bone.
• General visceral efferent or parasympathetic.
These fibers are secretomotor to the
submandibular and sublingual salivary gland,
lacrimal gland, and glands of the nose, the
palate and the pharynx.

5.  General visceral afferent component carries afferent
impulses from the previously mentioned glands.
 Special visceral afferent fibers carry taste sensations
from the anterior two-thirds of the tongue except
from valate papillae and from palate.
 General somatic afferent fibers probably innervate a
part of the skin of the ear. The nerve

6. does not give any direct branches to the ear,
but some fibers may reach it through
communications with the vagus nerve.
Proprioceptive impulses from muscles of face
travel through branches of trigeminal nerve to
reach the mesencephalic nucleus of the nerve.

8. Nuclei
The fibers of the nerve arise from 4 nuclei
situated in the lower pons.
1. Motor nucleus of branchiomotor
2. Superior salivatory nucleus or
parasympathetic
3. Lacrimatory nucleus is also parasympathetic
4. Nucleus of tractus solitarius which is
gustatory and also receives afferent fibers
from the glands

9. • The motor nucleus lies deep in the reticular
formation of the lower pons.
• The part of the nucleus that supplies muscles
of the upper part of the face receives
corticonuclear fibers from the motor cortex of
both the right and left sides.
• The part of the nucleus that supplies muscles
of the lower part of the face receive
corticonuclear fibers only from the opposite
cerebral hemisphere.

10. Course and Relations
• The facial nerve is attached to the brainstem
by 2 roots, motor and sensory (nervus
intermedius).
• The 2 roots of the facial nerve are attached to
the lower border of the pons just medial to
the 8th cranial nerve.
• The 2 roots run laterally and forwards, with
the 8th nerve to reach the internal acoustic
meatus.

11. • Inside the meatus, the motor root lies in a
groove on the 8th nerve, with the sensory root
intervening.
• Here the 7th and 8th nerves are accompanied
by labyrinthine vessels.
• At the bottom or fundus of the meatus, the 2
roots. Sensory and motor use to form a single
trunk, which lies in the petrous part of
temporal bone.

12. • Within the canal, the course of the nerve can
be divided into 3 parts by 2 bends.
• The first part is directed laterally above the
vestibule
• The second part runs backward in relation to
the medial wall of the middle ear, above the
promontry.
• The third part is directed vertically
downwards behind the promontry.
• The 1st bend at the junction of the 1st and 2nd
parts is sharp. It lies over the anterosuperior
part of the promontry called the genu.

13. • The 2nd bend is gradual, and lies b/w
promontry and aditus to mastoid antrum
• The facial nerve leaves the skull by passing
through the stylomastoid foramen.
• In its extracranial course, the facial nerve
crosses the lateral side of the base of styloid
process.
• It enters the posteromedial surface of parotid
gland, runs forwards though the gland
crossing the retromandibular vein and ECA.

14. • Behind the neck of the mandible it divides
into its 5 terminal branches which emerge
along the anterior border of the parotid gland.

15. Branches and Distribution

16. Within the facial canal
• Greater petrosal nerve
• Nerve to stapedius : arises opposite the
pyramid of middle ear and supplies the
stapedius muscle.

17. • Chords tympani : arises in the vertical part of
facial canal about 6 mm above the
stylomastoid foramen. It carries preganglionic
secretmotor fibers to the submandibular and
sublingual salivary glands and taste fibers
from the anterior two-thirds of the tongue.

18. At its exit from stylomastoid foramen
• Posterior auricular : arises just below the
stylomastoid foamen and supplies auricularis
posterior, occipitalis and intrinsic muscles on
the back of auricle.
• Digastric : arises close to the posterior
auricular. It is short and supplies the posterior
belly of the digastric.
• Stylohyoid : arise with the digastric branch, is
long and supplies stylohyoid muscle.

19. Terminal branches within parotid gland
• Temporal : cross zygomatic arch and supply
auricularis anterior, auricularis superior,
intrinsic muscles on the lateral side of ear,
frontalis, orbicularis oculi, corrugator supercili.
• Zygomatic : run across the zygomatic bone
and supply the orbicularis oculi.
• Buccal : 2 in number. Upper branch runs
above the parotid gland and lower below it

20. and supplies the muscle in that vicinity.
• Marginal mandibular : runs below the angle of
mandible deep to platysma. It crosses the
body of mandible and supplies muscles of the
lower lip and chin.
• Cervical : emerges from apex of parotid gland,
and runs downwards and forwards in the neck
to supply the platysma.

22. Ganglia

23. Geniculate ganglion
• Located on the 1st bend of facial nerve, in
relation to the medial wall of the middle ear.
• It is a sensory ganglion.
• The taste fibers present in the nerve are
peripheral processes of pseudounipolar
neurons present in the geniculate ganglion.

24. Submandibular ganglion
• Parasympathetic ganglion.
• For relay of secretomotor fibres to the
submandibular and sublingual glands.

25. Pterygopalatine ganglion
• Parasympathetic ganglion.
• Secretomotor fibers meant for the lacrimal
gland relay in this ganglion.

26. Clinical anatomy
• Supranulear and infranuclear lesions.
• In supranulear lesions; usually a part of
hemiplegia, only lower part of the opposite
side of the face is paralyzed. The upper part
with the frontalis and orbicularis oculi escapes
due to bilateral representation in the cerebra
cortex.

27. • In infranuclear lesions, known as Bell’s palsy,
the whole of the face of the same side gets
paralyzed. The face becomes asymmetrical
and is drawn up to the normal side. The
affected side is motionless. Wrinkles
disappear from the forehead. Eye cannot be
closed. Food accumulates b/w cheek and
teeth during mastigation.

28. • The symptoms according to the level of injury
of facial nerve.
• At internal auditory meatus; loss of
lacrimation, stapedial reflex, taste from most
of anterior two-third of tongue, lack of
salivation and paralysis of muscles of facial
expression.
• Below geniculate ganglion; loss of stapedial
reflex, taste from anterior two-

29. third of tongue, lack of salivation and paralayis
of facial expression muscles.
• Region b/w nerve to stapedius and chorda
tympani : loss of taste from anterior two-third
of tongue, lack of salivation and paralysis of
facial expression muscles.
• Region below stylomastoid foramen : paralysis
of facial expression muscles.

30. THANKS