The document provides an overview of the 12 pairs of cranial nerves: - It describes the names, numbers and basic functions of each cranial nerve. - It discusses the nuclei, pathways and branches of several key nerves - the trigeminal, facial, glossopharyngeal and vagus nerves - in more detail. - It explains that cranial nerves have both sensory and motor components, and lists their functional roles like proprioception, vision, taste, etc.

2. DR PALLAV RAJ

3. CONTENTS
 Introduction
Functional component
 Cranial nerves
 Course
 Surgical anatomy
 Conclusion
 Reference

4. INTRODUCTION

5. Nervous
System
Central
Nervous
System
Brain
Spinal Cord
Peripheral
Nervous
System
12 pairs of
Cranial Nerves
31 pairs of
Spinal nerves

6. CRANIAL NERVES
I. Olfactory
II. Optic
III. Occulomotor
IV. Trochlear
V. Trigeminal
VI. Abducens

7. VII. Facial
VIII. Vestibulocochlear
IX. Glossopharyngeal
X. Vagus
XI. Accessory
XII. Hypoglossal

8. FUNCTIONAL COMPONENTS
In addition to having similar somatic and
visceral components as spinal nerves, some
cranial nerves also contain special sensory
and motor components

9. Innervations of the musculature derived from
the five pharyngeal arches are
 First arch : Trigeminal Nerve
 Second arch: Facial Nerve
 Third arch: Glossopharyngeal Nerve
 Fourth arch: Superior laryngeal branch of
Vagus
 Sixth arch : Recurrent laryngeal branch of
Vagus

10. Functional
Component
Abbrev
iation
General Function Cranial Nerves
General Somatic
Afferent
GSA Perception of touch, pain,
temperature
Trigeminal, Facial, Vagus
General Visceral
Afferent
GVA Sensory input from viscera Glossopharyngeal, Vagus
Special Afferent SA Smell, Taste, Vision,
Hearing and Balance
Olfactory, Optic, Facial,
Vestibulocochlear,
Glossopharyngeal, Vagus
General Somatic
Efferent
GSE Motor innervations to
skeletal muscles
Oculomotor, trochlear,
Abducent, Accessory,
Hypoglossal
General Visceral
Efferent
GVE Motor innervations to
smooth muscles, heart
muscles and glands
Oculomotor, facial,
glossopharyngeal, vagus
Special Visceral
Efferent/ Branchial
Motor
BE Motor innervations to
skeletal muscles derived
from pharyngeal arch
mesoderm
Trigeminal, Facial,
Glossopharyngeal, Vagus

11. MOTOR

12. SENSORY

13. SENSORY/
AFFERENT
OLFACTORY
OPTIC
VESTIBULO
COCHLEAR
MOTOR/
EFFERENT
OCCULOMOTOR
TROCHLEAR
ABDUCENS
ACCESSARY
HYPOGLOSSAL
MIXTURE
TRIGEMINAL
FACIAL
VAGUS
GLOSSO
PHARYNGEAL

14. I - OLFACTORY NERVE
Special Afferent
Smell
15-20 pairs of olfactory nerves

16. Olfactory cells
Nerves pass through the cribriform plate of
the ethmoid bone
Olfactory bulb(are prolongation of
telencephalon) having mitral cells in the
anterior cranial fossa
Olfactory tract
Olfactory cortex

17. lateral Olfactory stria
Infro medial surface of the temporal lobe
(piriform plate)

19. II- OPTIC NERVE
 Special Afferent
 Vision
 It is not a true cranial nerve but rather an
extension of the brain carrying afferent
fibres from the eyeball to the visual
centres of the brain

20.  Axons of the
ganglion cells
make up the optic
nerve
 Optic disk is the
central collecting
point for these
axons

22. The optic nerve leaves the orbit through optic
foramen and then unite with each other to form
the optic chiasma
Fibres from the nasal half cross to the opposite
side but the temporal fibres remain uncrossed
Laterally the termination of ICA is related to the
chiasma

23. Posterior to the chiasma, optic nerves continue as the
optical tract
Most of the fibres synapse with the lateral geniculate body
in the thalamus
From here some of the fibres go via the optic radiation to
the occipital cortex
Those concerned with the pupillary reflex go to the
midbrain

24. Bipolar cells
Optic nerve
Optic Canal
Optic Chiasma
Optic Tract
Lateral Geniculate
nucleus
Primary Visual cortex
of Occipital Lobe
VISUAL PATHWAY

25. III- OCULOMOTOR NERVE
 General Somatic
Efferent
 General Visceral
Efferent
 General somatic
afferent
 Innervates sphincter
pupillae for pupillary
constriction and cilliary
muscles for

26. Nucleus of this nerve lies in the midbrain(ventromedial part of
central gray matter)
Nerve passes between the posterior cerebral and superior
cerebral arteries, then passes on the lateral side of the
posterior communicating artery
Nerve enters cavernous sinus by piercing the posterior part of
its roof on the lateral side of the posterior clinoid process
Passes through the sup. orbital fissure into the orbit as upper
and lower divisions

28.  This nerve is the motor nerve to
 Smaller upper division supplies
 Levator palpebrae superioris
 Superior rectus
 Larger lower division supplies
 Inferior rectus
 Medial rectus
 Inferior oblique

29. IV – TROCHLEAR NERVE
 General somatic efferent
 Supplies the superior oblique
muscle
 Only nerve to exit from the posterior
surface of the brainstem

30. The nucleus is in the mid brain and the nerve
fibres cross midline
It passes forward in the sub-arachnoid space
Pierces the dura mater to lie in the lateral wall
of the cavernous sinus
Nerve enters the orbit through the superior
orbital fissure

31.  In the orbit it passes above the origin of the
levator palpebrae superiors and ends by
supplying the superior rectus on it’s orbital
surface

33. TRIGEMINAL NERVE
 Largest cranial nerve
 Nerve of the first brachial
arch.
 Small motor root and
large sensory root
 It has three divisions:
1. Opthalmic
2. Maxillary
3. Mandibular

35. TRIGEMINAL NERVE – NUCLEAR ORIGIN
 There are 4 trigeminal nuclei .
 One motor and three sensory nuclei.

36. Exists from the
anterolateral surface of
the pons as a large
sensory root and small
motor root
Continues to posterior
cranial fossa
Middle cranial fossa by
passing over the medial
tip of petrous temporal
bone

37. In middle cranial fossa the sensory root expands into
trigeminal ganglion which lies in trigeminal depression
The motor root is below and completely separate from
the sensory root at this point
Three terminal divisions of trigeminal nerve arise from
the ganglion
Ophthalmic, maxillary, mandibular

38. OPTHALMIC DIVISION
 Smallest of the three branches
 Purely sensory
 Passes forward in the dura matter of the lateral wall of
cavernous sinus.
 Leaves the cranial cavity and enters through superior
orbital fissure
 Supplies
 Eyeballs , Lacrimal glands
 Mucous membrane of nose and paranasal sinuses
 Skin of the forehead , eyelids, nose.

40. LACRIMAL BRANCH
 Course
 Passes into orbit at lateral angle of superior orbital fissure
 Then in anterolateral direction to reach lacrimal gland
 Zygomatic nerve communicates with lacrimal nerve
 Supplies
 Lacrimal gland
 Conjunctiva
 Contents of the eyes
 Frontal sinus
 Ethmoidal cells
 Upper eyelid
 Dorsum of nose
 Anterior part of scalp

41. FRONTAL
 The largest branch of the Ophthalmic division.
 It begins in the lateral wall of the anterior part of the cavernous
sinus. It enters the orbit through the superior orbital fissure,
midway between the apex and base of the orbit.
 Divides into two branches
1. Supratrochlear
2. Supraorbital

42.  Supraorbital
 Passes forward & leaves orbit
through supraorbital foramen
 Supplies:
Skin of upper eyelid , Forehead ,
Anterior scalp region to the vertex
of skull.
 Supratrochlear
 Passes toward upper medial
angle of orbit
 Supplies:
Skin of upper eyelid ,Lower medial
portion of forehead.

43. NASOCILLIARY BRANCH OF OPTHALMIC NERVE
 Enters orbit through superior orbital fissure.
 Travels along the medial border of the orbital roof
 Branches in
 Orbit
 Nasal cavity
 Face

44. BRANCHES OF NASOCILLIARY NERVE
 Long root of the cilliary ganglion
 Sensory fibers
 Pass through ganglion without synapsing
 Continue on to eyeball
 Long cilliary nerves
 Usually two or three
 Post ganglionic fibers from superior cervical ganglion
 Distributed to iris & cornea

45.  Posterior ethmoid nerve
 Distributed to mucous membrane lining
 Posterior ethmoidal cells
 Sphenoid sinus
 Anterior ethmoid nerve
 Supplies
 Anterior and middle ethmoidal cells
 Frontal sinus
 In upper part of nasal cavity divides into
 Internal nasal branch
 External nasal branch

46. MAXILLARY NERVE
Passes forward in the dura
matter of the lateral wall of
cavernous sinus inferior to the
opthalmic nerve
Leaves the cranial cavity
through foramen rotundum
Passes through the ptyergopalatine
fossa and the inferior orbital
fissure

47. Br. in middle
Cranial fossa
Single branch-
Middle
meningeal
nerve
Br. in
pterygopalatine
fossa
Zygomatic
nerve
Pterygopalatine
nerve
Posterior
superior
alveolar nerve
Br. In
infraorbital
Groove & canal
Middle superior
alveolar nerve
Anterior
superior
alveolar nerve
Br. On face
Inferior
Palpebral
Lateral nasal
Superior
labial

48. THE PTERYGOPALATINE BRANCHES
 Branches of Distribution.—
 Orbital :
Periosteum of the orbit
 Nasal:
Superior and middle concha
Lining of posterior of
ethmoidal sinus
Posterior portion of nasal
septum

49. ZYGOMATIC BRANCH
Arises in the pterygopalatine fossa
Enters the orbit by the inferior orbital fissure
Divides into two branches,
 zygomaticotemporal
Sensory innervation to skin on the side of forehead
 zygomaticofacial.
Prominence of the cheek

50.  Palate
 Greater palatine:
• Sensory innervations to
palatine soft tissues till the
first premolar.
 Lesser palatine:
• supplies mucous membrane
of the soft palate tonsillar
region.
 Pharynx
• Mucous membrane of the
nasal part of pharynx,
posterior to auditory tube.

51. THE POSTERIOR SUPERIOR ALVEOLAR
BRANCHES
 Leave maxillary division
before entering inferior
orbital fissure
 Posterior surface of
maxilla
 Supplies
 Mucous membrane of
maxillary sinus
 Maxillary molar &
gingiva

52. THE MIDDLE SUPERIOR ALVEOLAR BRANCH
 Leaves the maxillary
nerve in posterior part of
infraorbital canal
 Downward & anteriorly
toward apices of
maxillary bicuspids
 Supplies
1. Maxillary bicuspids
2. Mesiobuccal root of
maxillary 1st molar

53. THE ANTERIOR SUPERIOR ALVEOLAR BRANCH
 Descends from infraorbital nerve inside
infraorbital foramen in anterior part on
infraorbital canal.
 Supplies
 Central incisors
 Lateral incisors
 Cuspid teeth

54. BRANCHES ON THE FACE
 The Inferior Palpebral Branches
 Skin and conjunctiva of the lower
eyelid
 The External Nasal Branches
 The skin of the side of the nose.
 The Superior Labial Branches
 Skin & mucous membrane of
upper lip.

55. MANDIBULAR NERVE
Leaves the inferior margin
of trigeminal ganglion
Leaves the skull through
the foramen ovale.
The motor root also passes
through the foramen ovale.
Unites with sensory
component of mandibular
nerve outside the skull

56. • Meningeal
• Nerve to medial pterygoidTrunk
• Deep temporal
• Lateral pterygoid
• Massetric
• Buccal
Anterior
division
• Auriculotemporal
• Lingual
• Inferior alveolar
Posterior
division

57. MENINGEAL BRANCH
 Given off just after
union of sensory &
motor root.
 Enter foramen
spinosum
 Accompanies middle
meningeal artery
 Supplies dura mater
of middle cranial
fossa

58.  Supplies medial
pterygoid
 Branch to
a. Otic ganglion
b. Tensor tympani
c. Tensor veli palatini
 Nerve to medial pterygoid

59.  Nerve to lateral pterygoid:
 Supplies lateral pterygoid muscle
 Masseter nerve
 Passes above lateral pterygoid & enter
masseter muscle
 Deep temporal nerve
Anterior, middle & posterior deep temporal
nerves
 Pass upwards to reach deep surface of
temporalis
 Buccal nerve
 Anteriorly & laterally between two heads
of lateral pterygoid.
At about the level of 2nd & 3rd molar.
ANTERIOR DIVISION

60. AURICULOTEMPORAL NERVE
 Arises by two roots which
form a ring through middle
meningeal artery passes.
 Backward in infratemporal
fossa & crosses neck of
mandible laterally behind
TMJ
 Branches
1. Auricular
2. Superficial temporal
3. Auricular or TMJ
4. Secretomotor to Parotid

61.  Smaller of two branches
of posterior division
 Passes medially to lateral
pterygoid muscle
 Lies parallel to inferior
alveolar nerve
 Passes deep, reach side
of the base of tongue.
 Passes forward, loops
downward & medially
beneath submandibular
duct.
Lingual nerve

62.  As lingual nerve passes medially to external pterygoid, it is joined
by chorda tympani nerve.
 It supplies:
i. Mucous membrane of the floor of the mouth.
ii. Gingiva on the lingual of the mandible.
 Convey Secretory fibers
 Lingual nerve carry three type of fibers
 Fiber for ordinary sensation
 Fibers for taste
 Secretomotor fibers

63. INFERIOR ALVEOLAR NERVE
Passes downward on medial side of lateral pterygoid &
mandibular ramus
In mandibular foramen, descends & distributed throughout
mandible
Branches to mandibular teeth & reach mental foramen
Two terminal branches, Mental nerve& incisive nerve
leave through mental foramen

65. VI – ABDUCENS NERVE
 General somatic efferent and afferent
 Supplies the lateral rectus muscle

66. Arises from the brain stem between the pons
and medulla
It passes upward forward and laterally through
the cisterna pontis to reach the cavernous
sinus
Lying at first lateral then infero lateral to the
Internal carotid artery
Nerve enters the orbit through the medial part of
superior orbital fissure
Ends by supplying the lateral rectus muscle
ocular surface

68. VII - FACIAL NERVE
 General somatic
afferent
 Special visceral
afferent
 General visceral
afferent
 Special visceral
efferent
 General visceral
efferent

71.  Sensory supply to parts of external acoustic
meatus and deeper part of auricle
 Special taste sensation from anterior two
third of the tongue
 Parasympathetic supply to lacrimal gland,
sub mandibular and sublingual salivary
glands, mucous membranes of the nasal
cavity, hard and soft palate

72.  Motor innervation to muscles of facial
expression, scalp ( derived from the second
arch)
stapedius
posterior belly of digastric
stylohyoid muscles

73. Facial nerve is attached to the lateral surface of
the brain stem, between pons and medulla
Consists of larger motor root and small sensory
root ( intermediate nerve)
They leave the cranial cavity through the
internal acoustic meatus

75. Facial nerve is closely associated with the
vestibulocochlear nerve
The two roots fuse and enters the facial canal
in the petrous temporal bone
Near this point the nerve enlarges as the
geniculate ganglion

77. It gives of the greater petrosal nerve at this
bend
Facial nerve continues along the bony canal
Gives off the nerve to stapedius and chorda
tympani before exiting the skull through the
stylomastoid foramen

79.  Within the facial
canal
 Greater petrosal
nerve(supply the
secretomotor
fibers to lacrimal
gland and
mucous glands of
nasal cavity and
palate.)

81.  Nerve to stapedius supplies the stapedius muscle
 Chorda tympani
Consist two types of fibers
i. Preganglionic parasympathetic (GVE) fibers,
provides secretomotor supply to submandibular &
sublingual glands.
ii.Special viseral afferant fibers
carries taste sensation from ant. 2/3 of the
tongue.

82.  At it’s exit from the
stylomastoid foramen
 Posterior auricular
Auricularis posterior
Occipitalis
Intrinsic muscle of the back of
the auricle
 Digastric
 Post. Belly of digastric
 Stylohyoid
 Stylohyoid muscles

83. Terminal branches within
the parotid gland
 Temporal
 Zygomatic
 Buccal
 Marginal mandibular
 Cervical
Communicating branches to
adjacent cranial and spinal
nerves

84.  Temporal Branch
o Auricularis anterior
o Auricularis superior
o Frontalis
o Orbicularis oris
o Corrugator supercilli

85.  Zygomatic:
 Orbicularis oris
 Marginal mandibular
 Muscles of lower lip and chin
 Cervical branch
 Platysma

86. VIII –VESTIBULOCOCHLEAR NERVE
 Special Afferent
 Hearing and
balance
 Vestibular
component for
balance
 Cochlear
component for
hearing

88.  After emerging from the internal acoustic
meatus it crosses the posterior cranial fossa
within the substance of the petrous part of
temporal bone
 The nerve attaches to the lateral surface of
the brainstem, between pons and medulla
 It is closely associated with the facial nerve

90.  Vestibular ganglia (consist of bipolar sensory
neurons)
divides in 3 distinct branches
Superior, inferior & singular nerve
innervates the sensory receptor for
equilibrium(cristae ampullaris and maculae)in
membranous labyrinth of int. ear.
The cochlear nerve ganglion is called spiral ganglion &
innervates the sensory receptor of hearing – the
organ of Corti.

91. IX – GLOSSOPHARYNGEAL NERVE
 General somatic
afferent
 Special visceral
afferent
 General visceral
afferent
 General visceral
efferent
 Special visceral
efferent

92.  Motor supply to
stylopharyngeus
 Secretomotor to parotid
gland
 Gustatory to post. one
third of tongue
 Sensory to pharynx,
tonsil, soft palate, post.
one third of tongue,
carotid body and carotid
sinus

93. Arises as several rootlets on the anterolateral surface of the
upper medulla oblongata
The rootlets cross the posterior cranial fossa
Enter the jugular foramen
Merge to form glossopharyngeal nerve before exiting from
jugular foramen
Within or immediately outside jugular foramen are superior
and inferior ganglia

95. In the jugular foramen the nerve is lodged in the deep
groove and is separated from vagus and accessory nerves.
Outside the foramen it passes forward between the
internal jugular vein and internal carotid artery.
It turns forward winding round the lateral aspect of
stylopharyngeus (passes between external and internal
carotid artery)reaches the pharynx and gives away
pharyngeal branches.
It enters the submandibular region by passing deep to
hyoglossus and divides into tonsillar and lingual branches.

97.  Tympanic branch
(jacobson’s nerve)
 Secretomotor supply of
parotid gland and other
small glands in the vestibule
of the mouth
 Motor branch:
 stylopharyngeus:
 Carotid sinus nerve:
 carotid sinus & body

98.  Pharyngeal branches:
 Mucous membrane and serous glands of oropharynx
 Taste fibres
 Tonsillar branch:
 Mucous membrane of the palatine tonsil & palate
 Lingual
 Posterior one third of the tongue taste & general
sensation

99. X – VAGUS NERVE
 General somatic
afferent
 Special visceral
afferent
 General visceral
afferent
 General visceral
efferent
 Special visceral
efferent

101.  Sensory supply to larynx, laryngopharynx,
deeper part of auricle, part of external
acoustic meatus and dura in the posterior
cranial fossa
 Sensory from aortic body chemoreceptors
and aortic arch baroreceptors, esophagus,
bronchi, lungs, heart, and abdominal viscera
of foregut and midgut

102.  Taste from epiglottis and pharynx
 Innervates the smooth muscles and
glands in the pharynx, larynx, thoracic
viscera and abdominal viscera of the
foregut and midgut
 Innervates palatoglossus, muscles of soft
palate ( except tensor veli palatini),
pharynx ( except stylopharyngeus) and
larynx

103.  Vagus nerve arises as a group of rootlets
on the anterolateral surface of the
medulla oblongata just inferior to the
rootlets arising to form the
glossopharyngeal nerve
 Rootlets enter the jugular foramen

104.  In the foramen they
merge to form one fibre
 Leaves the cranial
cavity by passing
through the middle of
the jugular foramen
 The nerve descends
within the carotid
sheath in between and
posterior to the internal
jugular vein and
common and internal
carotid artery

105.  Right vagus enters the
thorax by crossing the first
part of sub clavian artery
and inclining medially
behind the brachiocephalic
vessels
 Left vagus enters by
passing between the left
common carotid and left
sub clavian arteries behind
internal jugular and
brachiocephalic veins

106.  Vagus bears two ganglia
 Superior
 Lies in the jugular
foramen
 Inferior
 Lies below the base of the
skull
 Formed where accessory
portion of the spinal
accessory joins the vagus

107.  Branches
 Superior ganglion, in the jugular foramen
 Meningeal : Supplies dura of the posterior
cranial fossa
 Auricular : Supplies concha, root of the auricle,
posterior half of external auditory meatus and
the tympanic membrane
 Communicating branches to the
glossopharyngeal and cranial roots of
accessory nerve

108.  Inferior ganglion in the neck
 Pharyngeal : forms the pharyngeal plexus and
supplies the muscles of the pharynx and soft
palate
 Carotid : supplies the carotid body and sinus
 Sup. Laryngeal
 External : supplies cricothyroid, branches to inferior
constrictor and to the pharyngeal plexus
 Internal : Supplies the mucous membrane of the
larynx upto the vocal folds

109. Recurrent laryngeal
 Intrinsic muscles of larynx
except cricothyroid
 Sensory nerves to larynx
below the level of vocal
chords
 Cardiac branches to deep
cardiac plexus
 To trachea and oesophagus
 To inferior constrictor

110.  Cardiac branches
 They go to the
superficial cardiac
plexus and the
deep cardiac
plexus

111. XI – ACCESSORY NERVE
 General somatic
efferent
 It has two roots :
cranial and spinal
 Cranial root is
accessory to vagus
 Motor root arise from
the motor neurons of
the upper segments of
cervical spinal cord

112.  Spinal root supplies the
sternocleidomastoid
muscle and trapezius
muscle

113.  Cranial root is distributed through the
branches of vagus to the muscles of palate(
except tensor palati & tympani)
 All intrinsic muscle of larynx
 All pharynx muscle except stylopharangeus

114. The cranial roots emerge from posterolateral
sulcus of the medulla
In the jugular foramen the cranial root briefly
unites with the cervical root and again
separates as it passes out of the foramen
Cranial nerve fuses with the vagus and the
inferior ganglion and is distributed through
the branches of the vagus

115. The cervical roots unite to form a single
trunk in the vertebral canal and enter the
cranium through foramen magnum
Along with glossoparyngeal and vagus it
reaches the jugular foramen
It leaves the skull through the middle part of
the jugular foramen

116.  Extracranially the nerve
descends vertically
between internal jugular
vein and internal carotid
artery deep to the parotid
and to the styloid process
 Then it runs downwards
and backwards superficial
to the internal jugular vein
and deep to the SCM

118. XII – HYPOGLOSSAL NERVE
 General somatic
efferent
 Supplies the all
intrinsic and extrinsic (
except palatoglossus)
of the tongue

120. It arises from the anterior surface of the
medulla,
Passes laterally across the posterior cranial
fossa and exists through the hypoglossal
canal
It first lies deep to the internal jugular vein then
crosses the vagus laterally and reaches in
front

121. It curves forward, hooks around the lower
sternocleidomastoid branch of occipital
artery, crosses the ICA and ECA and the loop
of lingual artery and passes deep to post
belly of digastric to enter the submandibular
region
Nerve then continues forward on the
hyoglossus and genioglossus, enters the
substance of the tongue to supply the
muscles

123. BRANCHES
 Meningeal branch
 Styloglossus
 Hypoglossus
 Genioglossus
 Geniohyoid
 Thyrohyoid

124.  It supplies the extrinsic muscles
 Styloglossus
 Genioglossus
 Hyoglossus
 Intrinsic muscles
 Superior longitudinal
 Inferior longitudinal
 Transverse
 Vertical

125.  Conclusion

126.  Reference
 Lee McGregor’s Surgical Anatomy
 Grey’s Anatomy
 Sicher and DuBrul’s Oral anatomy
 B D Chaurasia’s Human Anatomy(5TH
edition)
 Vishram singh 2nd edition
 Internet