Download The Cranial Nerves

The Cranial Nerves
SHANDONG UNIVERSITY
Liu Zhiyu
Names of Cranial Nerves
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Ⅰ Olfactory nerve
Ⅱ Optic nerve
Ⅲ Oculomotor nerve
Ⅳ Trochlear nerve
Ⅴ Trigeminal nerve
Ⅵ Abducent nerve
Ⅶ Facial nerve
Ⅷ Vestibulocochlear nerve
Ⅸ Glossopharyngeal nerve
Ⅹ Vagus nerve
Ⅺ Accessory nerve
Ⅻ Hypoglossal nerve
I
Olfactory
(oh)
II
Optic
(oh)
III
Oculomotor
(oh)
IV
Trochlear
(to)
V
Trigeminal (1-3)
(touch)
VI
Abducens
(and)
VII
Facial
(feel)
VIII
Vestibulocochlear
(very)
IX
Glossopharyngeal
(good)
X
Vagus
(velvet)
XI
Accessory
(ah)
XII
Hypoglossal
(heaven)
How to Remember CN I-XII
Oh! Oh! Oh!
To Touch And Feel
Very Good Velvet!
Ah Heaven!
Functional Components
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General somatic afferent fibers (GSA): transmit
exteroceptive and proprioceptive impulses from head
and face to somatic sensory nuclei
Special somatic afferent fibers (SSA): transmit
sensory impulses from special sense organs of vision,
equilibrium and hearing to the brain
General visceral afferent fibers (GVA): transmit
interoceptive impulses from the viscera to the visceral
sensory nuclei
Special visceral afferent fibers (SVA): transmit
sensory impulses from special sense organs of smell
and taste to the brain
Functional Components
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General somatic efferent fibers (GSE): innervate
skeletal muscles of eye and tongue
Special visceral efferent fibers (SVE): transmit motor
impulses from the brain to skeletal muscles derived from
brachial (gill) arches of embryo. These include the
muscles of mastication, facial expression and swallowing
General visceral efferent fibers (GVE): transmit motor
impulses from the general visceral motor nuclei and
relayed in parasympathetic ganglions. The
postganglionic fibers supply cardiac muscles，smooth
muscles and glands
Classification of Cranial Nerves
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Sensory cranial nerves: are composed entirely of afferent
(sensory) nerve fibers bringing sensations the brain
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Motor cranial nerves: are composed entirely of efferent (motor)
fibers
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Ⅰ Olfactory nerve
Ⅱ Optic nerve
Ⅷ Vestibulocochlear nerve
Ⅲ Oculomotor nerve
Ⅳ Trochlear nerve
Ⅵ Abducent nerve
Ⅺ Accessory nerve
Ⅻ Hypoglossal nerve
Mixed cranial nerves: possess both sensory and motor fibers--
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Ⅴ
Ⅶ
Ⅸ
Ⅹ
Trigeminal nerve,
Facial nerve,
Glossopharyngeal nerve
Vagus nerve
Olfactory Nerve
Olfactory Nerve
Olfactory cells (SVA)→ Cribriform foramina → Olfactory bulb
Optic Nerve
Ganglion cells (SSA) → Optic canal → Lateral geniculate body
Vestibulocochlear Nerve
Vestibular ganglion(SSA) ↘
↗ Vestibular nuclei
Internal acoustic meatus
Cochlear ganglion (SSA) ↗
↘ Cochlear nuclei
Sensory Cranial Nerves
N.
Location of cell
body and axon
categories
Ⅰ
Terminal
nuclei
Main action
Olfactory cells (SVA) Cribrifom
foramina
Olfactory bulb
Smell
Ⅱ
Ganglion cells (SSA) Optic
canal
Lateral
geniculate
body
Vision
Ⅷ
Vestibular
ganglion(SSA)
Vestibular
nuclei
Equilibrium
Cochlear ganglion
(SSA)
Cranial
exit
Internal
acoustic
meatus
Cochlear nuclei Hearing
Motor Cranial Nerves
Ⅲ
Superior orbital fissure
Ⅳ
Ⅵ
Ⅻ
Hypoglossal canal
Ⅹ
Jugular foramen
Ⅺ
Oculomotor Nerve
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Components
 General somatic efferent fibers (GSE)
 General visceral efferent fibers (GVE)
Main action－supplies
 Superior, inferior and medial recti; inferior obliquus; levator palpebrae
superioris
 Sphincter pupillea and ciliary muscle
Ciliary ganglion : lies between optic nerve and lateral rectus
Oculomotor nerve
Abducent Nerve
Abducent nerve
Trochlear n.
Oculomotor n.
Abducent n.
Accessory Nerve
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Cranial roots
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Originate from nucleus ambiguus
Join the spinal roots to exit the
jugular foramen
Join the vagus nerve and distribute
to the muscles of pharynx and
larynx
Spinal roots
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Originate from nucleus of
accessory nerve
Ascend through the foramen
magnum and exit the cranium
through the jugular foramen
Innervate the sternocleidomastoid
and trapezius muscles
Hypoglossal Nerve
Nucleus of hypoglossal
→ Hypoglossal canal → Muscles of tongue
nerve( GSE)
Hypoglossal nerve
Motor Cranial Nerves
N.
Nucleus of origin and
axon categories
Cranial exit
Main action
Ⅲ
Nucleus of oculomotor
nerve (GSE)
Superior
orbital fissure
Motot to superior, inferior and
medial recti; inferior obliquus;
levator palpebrae superioris
Accessory nucleus of
oculomotor nerve (GVE)
Parasympathetic to sphincter
pupillea and ciliary muscles
Ⅳ
Nucleus of trochlear
nerve (GSE)
Superior
orbital fissure
Motor to superior obliquus
Ⅵ
Nucleus of abducent
nerve (GSE)
Superior
orbital fissure
Motor to lateral rectus
Ⅺ
Nucleus ambiguus
(cranial root, SVE)
Nucleus of accessory
nerve (spinal root, SVE)
Jugular
foramen
Motor to sternocleidomastoid
and trapezius
Ⅻ
Nucleus of hypoglossal
nerve( GSE)
Hypoglossal
canal
Motot to muscles of tongue
Mixed Cranial Nerves
Trigeminal Nerve (Ⅴ)
Components of fibers
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SVE fibers: originate from
motor nucleus of trigeminal
nerve, and supply masticatory
muscles
GSA fibers: transmit facial
sensation to sensory nuclei of
trigeminal nerve, the GSA
fibers have their cell bodies in
trigeminal ganglion, which lies
on the apex of petrous part of
temporal bone
Trigeminal Nerve (Ⅴ)
Ophthalmic nerve (Ⅴ1, sensory)
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Leave the skull through the superior orbital
fissure, to enter orbital cavity
Branches
 Frontal nerve
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Supratrochlear nerve
Supraorbital nerve
Lacrimal nerve
Nasociliary nerve
Trigeminal Nerve (Ⅴ)
Ophthalmic nerve
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Branches
 Frontal nerve
 Lacrimal nerve
 Nasociliary nerve
Distribution
 Sensation from cerebral dura mater
 Visual organ
 Mucosa of nose
 Skin above the eye and back of nose
Trigeminal Nerve (Ⅴ)
Maxillary nerve (Ⅴ2, sensory)
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Leave skull through foramen rotundum
Branches
 Infraorbital nerve
 Superior alveolar nerve
 Zygomatic nerve
 Pterygopalatine nerve
Trigeminal Nerve (Ⅴ)
Maxillary nerve
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Branches
 Infraorbital nerve
 Superior alveolar nerve
 Zygomatic nerve
 Pterygopalatine nerve
Distribution
 Sensation from cerebral dura mater
 Maxillary teeth and gum
 Mucosa of nose, mouth and maxillary
sinus
 Skin between eye and mouth
Trigeminal Nerve (Ⅴ)
Mandibular nerve (Ⅴ3, mixed)
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Leave the skull through the foramen ovale
to enter the infratemporal fossa
Branches
 Auriculotemporal nerve
 Buccal nerve
 Lingual nerve
 Inferior alveolar nerve
 Nerve of masticatory muscles
Trigeminal Nerve (Ⅴ)
Mandibular nerve
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Distribution
 Sensation from cerebral dura mater
 Teeth and gum of lower jaw
 Mucosa of anterior 2/3 of tongue and
floor of mouth
 Skin of auricular and temporal
regions and below the mouth
 Motor to masticatory muscles,
mylohyoid, and anterior belly of
digastric
Facial Nerve (Ⅶ)
Components of fibers
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SVE fibers originate from nucleus of facial nerve, and supply facial
muscles
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GVE fibers derived from superior salivatory nucleus and relayed in
pterygopalatine ganglion and submandibular ganglion. The
postganglionic fibers supply lacrimal, submandibular and sublingual
glands
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SVA fibers from taste buds of anterior two-thirds of tongue which cell
bodies are in the geniculate ganglion and end by synapsing with
cells of nucleus of solitary tract
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GSA fibers from skin of external ear
Facial Nerve (Ⅶ)
Course:
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Exits the brain stem through
the bulbopontine sulcus
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Leaves the skull through
internal acoustic meatus, facial
canal and stylomastoid
foramen, it then enters parotid
gland where it divides into five
branches which supply facial
muscles
Facial Nerve (Ⅶ)
Branches within the facial canal
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Chorda tympani: joins lingual branch
of mandibular nerve
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SVA fiber to taste buds on anterior
two-thirds of tongue
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GVE fibers relayed in
submandibular ganglion, the
postganglionic fibers supply
submandibular and sublingual
glands
Facial Nerve (Ⅶ)
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Greater petrosal nerve : GVE fibers pass to pterygopalatine ganglion
and there relayed through the zygomatic and lacrimal nerves to lacrimal
gland
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Stapedial nerve : to stapedius
Pterygopalatine ganglion
Facial Nerve (Ⅶ)
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Pterygopalatine ganglion:
lies in pterygopalatine fossa
under maxillary nerve
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Submandibular ganglion: lies
between lingual nerve and
submandibular gland
Facial Nerve (Ⅶ)
Branches outside of facial canal
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Temporal
Zygomatic
Buccal
Marginal mandibular
Cervical
Glossopharyngeal Nerve (Ⅸ)
Components of fibers
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SVE fibers: originate from nucleus ambiguus, and supply
stylopharygeus which elevates the pharynx during swallowing and
talking
GVE fibers: arise from inferior salivatory nucleus and relayed in otic
ganglion, the postganglionic fibers supply parotid gland
GVA fibers: visceral sensation from mucosa of posterior third of
tongue, pharynx, auditory tube and tympanic cavity, carotid sinus and
glomus, and end by synapsing with caudal part of nucleus of solitary
tract
SVA fibers: arise from the cells of inferior ganglion, the central
processes of these cells terminate in rostral part of nucleus of solitary
tract, the peripheral processes supply the taste buds on posterior third
of tongue
GSA fibers: The cell bodies are located in the superior ganglion. The
central process carry impulse from skin of posterior surface of auricle to
spinal nucleus of trigeminal n.
Glossopharyngeal Nerve (Ⅸ)
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Course:
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Exits the brain stem through the retroolivary sulcus
leaves the skull via jugular foramen
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Branches
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Lingual branches : to taste buds and mucosa of posterior third of tongue
Pharyngeal branches : take part in forming the pharyngeal plexus，
distribute to the walls of pharynx
Tympanic nerve: GVE fibers via tympanic and lesser petrosal nerves to otic
ganglion, with postganglionic fibers via auriculotemporal (Ⅴ3) to parotid
gland
Carotid sinus branch: innervations to both carotid sinus and carotid
glomus
Others: tonsillar and stylophayngeal branches
Otic ganglion: situated just below foramen ovale
Glossopharyngeal Nerve (Ⅸ)
Vagus Nerve (Ⅹ)
Components of fibers
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GVE fibers: originate from dorsal nucleus of vagus nerve, synapse in
parasympathetic ganglion, short postganglionic fibers innervate cardiac
muscles, smooth muscles and glands of viscera
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SVE fibers: originate from ambiguus, to muscles of pharynx and
larynx
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GVA fibers: The cell bodies are located in the inferior vagal ganglion.
The central process carry impulse from viscera in neck, thoracic and
abdominal cavity to nucleus of solitary tract
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GSA fibers: The cell bodies are located in the superior vagal ganglion.
The central process carry impulse from auricle, external acoustic
meatus and cerebral dura mater to spinal nucleus of trigeminal n.
Left Vagus Nerve
Course
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Enter thoracic inlet between left common
carotid and left subclavian arteries
Crosses the left side of the aortic arch where
left recurrent laryngeal nerve branches off
Passes posterior to left lung root contributing to
the pulmonary plexus
Descends on the anterior surface of the
esophagus and forms anterior esophageal
plexus
Forms anterior vagal trunk at esophageal
hiatus where it leaves thorax and passes into
abdominal cavity , then divides into anterior
gastric and hepatic branches
Right Vagus Nerve
Course
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Travels downward anterior to the right
subclavian artery and enter thoracic inlet on
right side of trachea
Passes posterior to right lung root
contributing to the pulmonary plexus
Then passes on to the posterior surface of
esophagus and forms posterior esophageal
plexus
Forms posterior vagal trunk at esophageal
hiatus where it leaves thorax and passes into
abdominal cavity, then divides into posterior
gastric and celiac branches
Vagus Nerve (Ⅹ)
Branches in neck
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Superior laryngeal nerve : passes
down side of pharynx and given rise
to
 Internal branch, which pierces
thyrohyoid membrane to
innervates mucous membrane of
larynx above fissure of glottis
 External branch, which
innervates cricothyroid
Cervical cardiac branches :
descending to terminate in cardiac
plexus
Others: auricular, pharyngeal and
meningeal branches
Vagus Nerve (Ⅹ)
Superior laryngeal nerve
Internal branch
External branch
Vagus Nerve (Ⅹ)
Branches in thorax
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Recurrent laryngeal nerves
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Right one hooks around right subclavian
artery, left one hooks aortic arch
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Both ascend in tracheo-esophageal groove
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Nerves enter larynx posterior to cricothyroid
joint, the nerve is now called inferior
laryngeal nerve
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Innervations: laryngeal mucosa below fissure
of glottis, all laryngeal muscles except
cricothyroid
Bronchial and esophageal branches