Download Cranial nerves

Cranial nerves
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Key Points of Learning

Name

Components

Passing through

Peripheral
distribution

Central connection

Function
Cranial nerves
Ⅰ olfactory
Ⅱ optic
Ⅲ occulomotor
Ⅳ trochlear
Ⅴ trigeminal
Ⅵ abducens
Ⅶ facial
Ⅷ vestibulocochlear
Ⅸ glossophryngeal
Ⅹ vagus
Ⅺ accessory
Ⅻ hypoglossal
Cranial nerves: connect with brain
Openings and fissures on base of skull for CN
CRANIAL NERVE
• General somatic motor (GSM)
• General visceral motor (GVM)
•
Special visceral motor (SVM)
• General somatic sensory (GSS)
• Special somatic sensory (SSS)
• General visceral sensory (GVS)
• Special visceral sensory (SVS)
Every pair of CN has not all of the above
components.
CRANIAL NERVE
Pure sensory CN
 olfactory n.
 optic n.
 vestibulocochlear n.
Olfactory nerve CN I
Pure sensory (SVS) --smell
Olfactory bulb of telencephalon
Leaves cranial cavity through
foramina in cribriform plate
Distributes to mucosa of superior
part of lateral and septal walls of
nasal cavity.
pure sensory (SSS)-- sight
Connects with optic chiasma
of diancephlon.
Leaves cranial cavity through
optic canal.
Distributes to retina of
eyeball
optic n.(Ⅱ)
optic nerve, chiasma, optic tract
vestibulocochlear n.
conveys impulses from inner ear
sense of position terminates in vestibular N
sense of hearing in cochlear N

Pure sensory (SSS)

Internal acoustic
meatus → internal ear

Vestibular nerve is
responsible for
equilibrium

Cochlear nerve is
responsible for hearing
Pure motor CN

oculomotor n.

trochlear n.

abducens n.

accessory n.

hypoglossal nerve
oculomotor n. trochlear n. abducens n.
Oculomotor n.(GSM and GVM)
 Midbrain
Superior orbital
fissure
Superior division--superior
rectus
& levator palpebrae superioris
Inferior
division supplies inferior
& medial rectus, & inferior oblique.
GVM
fibers—parasympathetic,
supply ciliary muscle and sphincter
pupillae.
Trochlear N
Pure
motor (GSM) ; midbrain ;
Superior orbital fissure ; Superior
oblique m
Abducens N
Pure
motor (GSM) ; Pons ;
Superior orbital fissure
Lateral
rectus m

Two roots

Pure motor

Medulla & spinal cord

Jugular foramen

Cranial root--joins X

Spinal root-sternocleidomastoid &
trapezius
accessory n.
Hypoglossal nerve

Pure motor (GSM)

Medulla

Hypoglossal canal

extrinsic and intrinsic muscles of tongue.
Mixed CN

trigeminal n.

facial n.

glossopharyngeal n.

vagus n.
Trigeminal nerve V

pons

Has three divisions: ophthalmic, maxillary, and
mandibular nerve

Has both sensory and motor components.

It is the main sensory nerve for head and face.

Its motor nerve innervates the muscles of mastication,
etc.
Ophthalmic
Superior orbital fissure
into orbital cavity
Maxillary-foramen
rotundum into
pteygopalatine
Mandibular –foramen
ovale
Trigeminal nerve –ophthalmic N

superior orbital fissure

Lacrimal nerve to lacrimal
gland.

Frontal nerve to forehead

Nasociliary nerve to
eyeball, part of nasal cavity,
and skin of dorsum of nose
from root to top.
Trigeminal nerve –maxillary N

foramen rotundum
pterygopalatine fossa
inferior orbital fissure,
sulcus, canal and foramen

to part of nasal cavity,
maxilla, upper teeth, and
skin between eye and
mouth
Mandibular n.

Lingual nerve to anterior 2/3
of tongue

Inferior alveolar nerve to
mandible, lower teeth, and chin

Buccal nerve to cheek

Auriculotemporal nerve to
parotid gland and temporal
region

SVM fibers supply muscles of
mastication, tensor veli
palatini, and tensor tempani,
etc.
tensor tympani M
anterior belly of digastric M
Sensory fibers of CN V
Facial nerve in the temporal bone and main branches and distribution

Mixed (SVM, GVM, SVS) Pons →
internal acoustic meatus→canal of facial
nerve→stylomastoid foramen parotid
gland

SVM fibers supply muscles of facial
expression & stapedius

GVM fibers synapse in pterygo-palatine
ganglion to supply lacrimal gland; in
submandibular ganglion submandibular &
sublingual gland

SVS fibers receive taste from anterior 2/3
of tongue
Facial nerve
facial n in the internal auditory meatus
facial n in the internal auditory meatus, canal, through the stylomastioid foramen
Facial nerve distributes to expression muscles
Facial nerve distributes to mucous of tongue
CN Ⅶ distributes to submandibular gland and sublingual gland
through the submadibular ganglion
glossopharyngeal n.



medulla
jugular foramen
GSS: carotid sinus and body,
oropharynx, and posterior 1/3
of tongue

SVS: receive taste from
posterior 1/3 of tongue

SVM: stylopharyngeus

GVM: synapse in otic ganglion
to supply the parotid gland
glossopharyngeal n.
To carotid body (chemoreceptors)
carotid sinus (baroreceptors )
To pharyngeal muscle, parotid salivary gland
to tongue general somatic and special taste sensory(posterior third)
The vagus nerve in the neck, thorax, and abdomen

Mixed; medulla;

jugular foramen; carotid
sheath , on the side of
mediastinum, esophgeal plexus,
esophgeal hiatus anterior and
posterior vagal trunks
The afferent fibers of vagus n.

GSS in tympanic membrane,
external autitory meatus,
and part of the concha of the
external ear.

GVS are distributed widely
throughout the mucous
membrane of the respiratory,
gastrointestinal system and
internal layer of the
cardiovascular.

chemoreceptors in aortic
bodies and baroreptors in
the aortic arch
Parasympathetic fibers in the vagus nerve
 the dorsal motor nucleus
of vagus.
 They are distributed
widely throughout the
respiratory, gastrointestinal
system and cardiovascular.
 GVM
• to the muscles of larynx and pharynx through the
superior laryngeal nerves and the recurrent nerves
• SVM
SUMMARIZE
Nerves of eye
Nerves of tongue
nerves of pharynx
……