This document provides an overview of the nerve supply of the head and neck region. It begins with an introduction to the nervous system, including the central and peripheral nervous systems. It then discusses the 12 cranial nerves in detail, including their origin, course, structures supplied, and clinical correlations. For each cranial nerve, it provides summaries of key branches and their functions. The document also briefly discusses the spinal nerves and covers topics such as neurons, neuroglial cells, and the development of the nervous system. Overall, the document concisely summarizes the anatomy and clinical relevance of the major nerves involved in innervating the head and neck.

1. Nerve supply of head and neck
region
Dr. Renuka Avinashe
Oral and maxillofacial Surgeon
PG 1
Under the guidance of –
Dr. Amarjeet Gambhir
Assistant Professor

2. Contents
• Introduction to nervous system
• Cranial nerves
• Spinal nerves
• Cranial nerves : origin
course
structures supplied
clinical correlation

3. Nervous system
Central nervous system
• Brain
• Spinal cord
Peripheral nervous system
1. Motor division
2. Sensory division
Motor division :
• Somatic nervous system
• Autonomous nervous
system

4. Peripheral nervous system
Somatic nervous system
- voluntary
Autonomous nervous system
- involuntary
 Sympathetic nervous
system
 Parasympathetic nervous
system
 Enteric nervous system

5. Peripheral nervous system
Sympathetic nervous system
• Origin – thoracolumbar
outflow : T2 –L2-L3
• Widely distributed
• Adrenergic system
Parasympathetic nervous system
• Origin – craniosacral
outflow : 3,7,9,10 , S2-S4
• In head ,neck and trunk
• Cholinergic system

6. ENTERIC NERVOUS SYSTEM
• It innervates viscera
* GIT
*Pancreas
*Gall bladder

7. NEURONS
• Structural and functional unit of nervous
system , made up of
• Cell body
• Cell processes : dendrites
: axons

8. NEURONS
TYPES
A/c to no. of processes
• Multipolar
• Bipolar
• Unipolar
• Psudounipolar
A/c to length
• Golgi type I
• Golgi type II
• Amacrine neurons

9. Neuroglial cells
• Astrocytes
• Oligodendrocytes
• Microglia
• Ependymal cells
• Schwann cells

10. Development of nervous system
Embryonic ectoderm
Neural plate
Neural crest cells :
PNS , ANS
Neural tube : CNS

11. CRANIAL NERVES
I. Olfactory
II. Optic
III. Occulomotor
IV. Trochlear
V. Trigeminal
VI. Abducent
VII. Facial
VIII. Vestibulocochlear (Statoacoustic / Auditory)
IX. Glossopharyngeal
X. Vagus
XI. Accessory
XII. Hypoglossal

12. Spinal nerves
31 pairs
• Cervical – 8
• Thoracic -12
• Lumbar -5
• Sacral -5
• Coccygeal -1

13. ATTACHMENT OF NERVES TO BRAIN

14. Origin
• 1,2 : forebrain
• 3,4: midbrain
• 5 : pons
• 6,7,8 : jun.between pons and medulla
• 9,10,11,12 : medulla
1,2,8 : pure sensory
3,4,6,11,12 : pure motor
Rest : mixed

15. NUCLEI
General Somatic Efferent (GSE)
Nuclei Supply skeletal muscle of somatic origin { 3, 4,6,12 }
1. Oculomotor Nucleus
2. Trochlear Nucleus
3. Abducent Nucleus
4. Hypoglossal Nucleus

16. Special Visceral Efferent (SVE)/Branchial Efferent Nuclei
1. Motor Nucleus of Trigeminal
2. Nucleus of Facial Nerve
3. Nucleus Ambiguus

17. General Visceral Efferent (GVE) Nuclei
1. Edinger – Westphal Nucleus
2. Lacrimatory Nucleus
3. Superior Salivatory Nucleus
4. Inferior salivatory nucleus
5. Dorsal nucleus of vagus

18. General Visceral Afferent (GVA) & Special Visceral Afferent
(SVA) Nucleus :
7, 9,10
1. Nucleus of Solitary Tract

19. General somatic afferent
• Superior sensory nucleus of trigeminal nerve
• Spinal nucleus
• Mesencephalic nucleus

20. Special somatic afferent nuclei
• Cochlear nuclei
• Vestibular nuclei

21. Cranial nerve nucleus

22. Olfactory nerve
• Transmits sense of smell
• Branches arise from sensory
cells of nasal mucosa, enter
cranial cavity as olfactory
filament through openings of
cribriform plate of ethmoid
bone
• Enter olfactory bulb singly
• Bulb is vestigial of olfactory
lobe of macrosmatic mammals.

23. Optic nerve
• Second pair of
cranial nerve
• Nerve of visual sense
• Arise in ganglion cells
of retina
• Enters cranial cavity
through optic
foramen

24. Occulomotor nerve
• Contains somatic & parasympathetic visceral
efferent fibres
• Somatic fibres responsible for most of the
extrinsic muscles of the eye
• Parasympathetic fibres relay in ciliary ganglion
• Postganglionic fibres arising from ciliary ganglion,
enter eyeball & supply ciliary muscles or muscles
of accommodation & sphincter of pupil
• Enters orbit through superior orbital fissure

25. 3rd nerve
Supplies :
• Levator palpebrae superioris
• Superior , medial ,inferior rectus
• Inferior oblique

26. Trochlear nerve
• Carries somatic fibers , motor .
• supply superior oblique muscle of eyeball
/ SO 4
• Passes through superior orbital fissure
• Only cranial nerve that emerges from dorsal
aspect of brain stem

29. Superior orbital fissure syndrome
A group of neurological deficits expressed by the
altered functions of nerves passing through the SOF
due to dislocated bony fragments or comminuted
fractures in the region of superior orbital fissure or
lesser wing of sphenoid nerve lesion .
Leads to :
1. Diplopia
2. Paralysis of extraocular muscles
3. Exopthalamos
4. Ptosis
5. Blindness in involvement of orbital apex

30. TRIGEMINAL NERVE
Largest cranial nerve ,
Nerve of first brachial arch
• Sensory fibres except proprioceptive fibres
arise in semilunar ganglion.
• Ganglia associated
1. ciliary
2. pterygopalatine
3.otic
4. submandibular

32. At meckel’s cave – apex of petrous temporal bone

33. COURSE

35. OPTHALMIC DIVISION
• 1st branch of V th cranial nerve
• Purely sensory & smallest of 3 divisions
• Supplies eyeball, conjunctiva, lacrimal gland, parts
of mucous membrane of nose & PNS & skin of
forehead, eyelids & nose
• Divides into 3 main branches just before passing
through superior orbital fissure –
1. Nasocilliary
2. Frontal
3. Lacrimal – smallest branch

37. Nasociliary nerve
Branches
1. Long ciliary nerve
2. Branch to ciliary ganglion
3. Posterior ethmoidal
4. Anterior ethmoidal -
• middle and ant. Sinuses
• Med. Internal nasal
• Lat.internal nasal
• External nasal
5 . Infratrochlear

38. Frontal
• Largest branch
`1. medial supraorbital nerve – skin of med
forehead,
2. lateral supraorbital nerve – skin of forehead
lat , scalp
3. supratrochlear nerve – skin of upper eyelid
and nasal root

39. Lacrimal nerve
• External branch
• Receives fibres from zygomatic nerve
• Contains post ganglionic parasympathetic
fibres for lacrimal gland .
• Also supplies lat. part of upper eyelid and
adjacent part of the skin

40. Maxillary nerve
• V 2 , purely sensory , arises from trigeminal
ganglion in middle cranial fossa
• Through for. Rotundum
• 3 branches
1. pterygopalatine nerve
2. infraorbital nerve
3. zygomatic nerve

41. Course
Trigeminal ganglion
Lateral wall of cavernous sinus
Foramina rotundum
Pterygopalatine fossa
Enters inferior orbital
fissure to enter orbital
cavity
Turns laterally and
comes out through
infraorbital foramina

43. MAXILLARY NERVE
Branches
Middle cranial
fossa
-middle meningeal
nerve {n sensory
to dura }
In infraorbital
groove
-1. MSA – only in 28%
person
- Supplies mx cuspids
- MB root of 1st molar
2. ASA – mx incisors
and cuspids
Terminal
branches
1. Palpebral
2.External nasal
3. Superior
labial

44. Zygomatic
nerve
• Zygomatic
temporal
• Zygomatic
facial
Sphenopala
-tine nerve
• Orbital
• G.P & L.P.
• Nasal
• Pharyngeal
br.
PSA
• To
maxillary
moalrs
except MB
root of first
molar
• Mucosa of
maxillary
sinus
Branches in pterygopalatine fossa

45. Infraorbital nerve
• Continuation of main trunk
passes through infraorbital fissure
enters orbit
runs in infraorbital groove
infraorbital foramina
br. ASA and MSA

46. Nerve protection
• Subciliary incision : infraorbital nerve is approx. 5-7
mm inferior to orbital rim and should be avoided
when periosteal incision is made .

47. Mandibular nerve
• Begins in middle cranial fossa , largest division
• Mixed nerve – large sensory and small motor
root
• Comes out through for. Ovale

50. Branches of V 3
Trunk
1. Meningeal br.
2. Nerve to med.
Pterygoid
-nerve to med.
Pterygoid
- t. palatini
-t. tympani
Anterior division
1. Deep
temporal nerve
2. Massetric
nerve
3. Nerve to lat.
pterygoids
4. Buccal nerve {
only sensory }
Posterior
division
1.
Auriculotempora
l nerve
2. Lingual nerve
3. Inferior
alveolar nerve
4. Nerve to
mylohyoid

51. AURICULOTEMPORAL NERVE
• Arises by two roots which runs backward
between neck of mandible and
sphenomandibular ligament
• Encircles around middle meningeal artery
• Auricular part : supply skin of tragus , upper
part of pinna , ext. acoustic meatus and
tympanic membrane
• Temporal part : skin of temple
• Secretomotor supply to parotid gland

52. Inferior salivatory nucleus
Glossopharyngeal nerve
Tympanic branch
Tympanic
plexus
Lesser
petrosal nerve
Relay in otic
ganglion
Auriculotemporal nerve ---parotid gland
Relation of
auriculotemporal nerve
to parotid gland

53. Lingual nerve
• Separates from IAN ,5-10 mm below cranial
base.
• Lies ant.and medial to IAN through its course
• It further descends between lat. & med.
Pterygoid muscle where it is joined by chorda
tympani .
• Then runs bet. Ramus and med. Pterygoid .

54. • Lies in direct contact with mandibular 3rd
molars between origin of sup. Constrictors &
mylohyoid .
• Runs on surface of genioglossus muscle
• Winds around duct of submandibular salivary
gland and gives multiple branches
• Enters tongue to supply muscles of tongue
after exchanging fibres with hypoglossal nerve

56. Inferior alveolar nerve
• Largest , terminal branch
• Before entering mandibular canal gives branch
to Mylohyoid , runs in mylohyoid groove
• supplies 1. mylohyoid muscle 2. ant.belly
of digastric.
Through canal gives 1. incisive branch
2. mental branch – to chin ,
lower lip

59. Trigeminal neuralgia

63. Frey’s syndrome / auriculotemporal nerve syn./ baillarger’s syn./ dupuy’s syndrome

66. 6th nerve
• Fibres emerges from pons from the groove between
pons and medulla .
• Passes through cavernous sinus and lies below ICA.
• Nerve enters through orbit through superior orbital
fissure .
• Supplies lateral rectus muscle.

67. Facial nerve
• Mixed nerve
• Contains two nerves – facial nerve proper and
intermediate nerve .

68. Course

70. Facial nerve
Facial nerve proper
Motor fibres for
• muscles of facial expression
• occipital
• Auricular
• platysma
• Stapedius
• Post. Belly of digastric
• Stylohyoid
Intermediate nerve
Proprioceptive fibres for
• Deep sensitivity to face
• Taste sensation for ant . 2/3
rd of tongue and palate
• Preganglionic fibres for
lacrimal gland
• Sublingual
• Submandibular salivary
gland
• Minor salivary gland

71. Nuclei
• Motor nucleus / brachiomotor
• Superior salivatory nucleus
• Lacrimatory nucleus
• Nucleus of tractus solitarius

76. Branches of facial nerve
Within facial canal
1. Greater petrosal
nerve
2. Nerve to Stapedius
3. Chorda tympani
At the exit from
stylomastiod foramina
1. post. Auricular nerve
2.Nerve to post. Belly
of Digastric nerve
3. Nerve to stylohyoid
Terminal branches
1.Temporal
2. Zygomatic
3.buccal
4. Marginal mandibular
5.Cervical

77. Nerve protection
• Incision is placed approx. 2cm behind the ramus and 1cm
below the pinna to avoid any injury .
landmark for nerve trunk identification :
1. Tragal pointer : 1cm deep and inferior
2. Tympanomastoid suture : 3.5 mm
3. Posterior belly of diagastric :7.5mm
( Indian j otolayngol Head Neck
Surg,2014;66-1: 63-68)

78. Temporal branch
• Emerges from parotid gland from its upper pole , in
front of superficial temporal artery .
• Branches : posterior br: to anterior and superior
auricular muscle
• anterior branches : to frontal muscle , superior of
orbicularis oculi , corrugator of eyebrow , slender
muscles of nose

79. Nerve protection during various approaches
• Subciliary approach : incision is extended approx. 2cm from the
lateral canthus without damaging anterior temporal branch
• Coronal / bitemporal approach :nerve lies 0.5 cm below the
tragus , crosses zygomatic arch at average distance of 2 cm from
anterior to anterior concavity of external auditory meatus .
• Preauricular approach : protected by incising through superficial
layer of temporalis fascia and periosteum of zygomatic arch not
more than 0.8 cm from anterior border of external auditory canal

80. Zygomatic nerve
• Leaves parotid at its anteriosuperior border.
• Crosses zygomatic bone
• Supplies inferior part of orbicularis oculi
muscle.

81. Buccal branch
• Emerges at anterior part of parotid
• Divided into upper and lower branches
• Upper Buccal : muscles of upper lip ,nose
• Lower buccal : buccinators, risorius muscle

82. Buccal branch
• Emerges at anterior part of parotid
• Divided into upper and lower branches
• Upper Buccal : muscles of upper lip ,nose
• Lower buccal : buccinators, risorius muscle

83. Mandibular branch
• Runs parallel to the lower border of mandible
• In their course , marginal mandibular crosses
facial artery and vein lying superficially to
them
• Supplies muscles of lower lip and mentalis
muscle.

84. • Incision should be placed at least 1.5 cm below the lower
border of mandible to avoid injury to marginal mandibular
branch of facial nerve

85. Cervical branch
• Leaves parotid gland slightly above its inferior
pole .
• Runs underneath platysma and supplies it .

86. Bell’s palsy

87. UMN & LMN Lesions

88. Vestibulocochlear nerve

89. 8th nerve
• Sensory nerve
• Has two roots - vestibular and cochlear
• Vestibular root : impulse from vestibular apparatus
/balance
• Cochlear root : transmit impulse from auditory
apparatus /sound
• Function : transmit sound and equilibrium from
internal ear to brain.

90. Glossopharyngeal nerve
• Emerges from lateral surface of medulla
oblongata & passes in front of vagus nerve
through jugular foramen
• Contains motor fibres
• Motor supply to stylopharyngeus muscle &
participates with vagus in supplying constrictors
of pharynx & palatopharyngeus muscle
• Sensory supply to parts of tonsil, adjacent
pharyngeal mucosa , base of tongue
• Taste sensation from vallate and foliate papillae

92. Glossopharyngeal neuralgia
Short sharp severe
attack of pain affecting
the posterior part of
pharynx or tonsillar area

93. Vagus nerve
Longest cranial nerve , widest distribution in body .
Originates in medulla oblongata
2 ganglions - superior and inferior ganglion

94. Vagus nerve
Superior ganglion branches
• Meningeal branch
• Auricular branch
Inferior ganglion branches
• Pharyngeal branches
• Superior laryngeal nerve
-external laryngeal nerve
-internal laryngeal nerve
• Recurrent laryngeal nerve
• Cervical carotid branches
• Anterior oesophageal
plexus
• Gastric , celiac ,hepatic
branches

95. Vagus nerve supplies
• Cricothyroid
• Levator veli palatini
• Salpingopharyngeus
• Palatopharyngeus
• Palatoglossus
• Palatopharyngeus
• Superior, middle , inferior pharyngeal constrictor .
• Muscles of larynx

96. Accessory nerve
• Cranial root : joins
vagus nerve and
innervates all
laryngeal muscles
except cricothyroid
• Spinal root :
innervates trapezius ,
SCM

97. Hypoglossal nerve
• Twelfth cranial nerve
• Arises from medulla oblongata
• Leaves the skull through hypoglossal canal
• Motor supply to all intrinsic & extrinsic
muscles of tongue except palatoglossus
• Joined by nerve that arises from the loop
between 1st & 2nd cervical nerves

98. • Most of these fibers get detached from
hypoglossal nerve as it reaches between internal
& external carotid artery & constitutes the
superior branch of the ansa cervicalis
• Joined by branches from 2nd & 3rd cervical
nerves (inferior branch of ansa cervicalis)
• From this loop branches to supply omohyoid,
sternothyroid, sternohyoid muscles
• Cervical fibers that do not get detached continue
in the sheath of hypoglossal nerve & branches off
into nerve for thyrohyoid & nerve for geniohyoid

100. Hypoglossal nerve injury
supranuclear lesion
• Paralysis without wasting
• Defective speech
• on protrusion deviates to opposite side

101. Hypoglossal nerve injury
infranuclear lesion
Unilateral Bilateral
• Complete paralysis
• Protrusion is impossible
• Swallowing ,speech affected
• Same side of lesion –
paralysis , deviates to
normal side .
• Gradual atrophy of
paralysed half

102. Eyes are window to soul ; face is window to brain !
Thank you !