Cranial Nerves Overview Table

Somatic

General

General

Visceral

CRANIAL

ORIGIN

COURSE

SENSORY

MOTOR

AUTONOMIC

NOTES & TESTS

Efferent

Somatic

Visceral

NERVE

& SIGNS OF

Efferent

Afferent

Afferent

DYSFUNCTION

I - Olfactory

Telencephalon

Fibers leave

Ipsilateral, does not

smell

x

via cribiform

x

synapse on thalamus,

x

x

*Smell*

Cell bodies in

olfactory mucosa

plate of

goes right to sensory

x

cortex; rarely tested in

ethmoid bone

clinical settings

Enters skull

Diencephalon

Affected by lesions along

II- Optic

@ optic canal

Vision

x

x

visual pathway, can

x

x

*Vision*

x

Ganglion cells of

after fiber

assess with

retina

Menace response

convergence

Pupillary light reflex

Mesencephalon

Fibers from motor

III - Oculomotor

nucleus thru

x

Eye

Smooth muscle

PLR,

Extraocular

Ciliary

Rostral course from

cavernous sinus to

of eye

ventrolateral

muscles

muscles of

x

x

pterygopalatine

exit @ orbital

movement

fossa

fissure

strabismus

eye

Rotational

Emerges from

Extraocular

IV - Trochlear

Mesencephalon

dorsal brainstem

Eye

x

x

strabismus,

muscles

x

x

x

Innervates 1

to cross midline

movement

external

ocular muscle

entirely

opthalmoparesis

Sensation to face,

Muscles of

skin of

Motor from pons,

Metencephalon

Facial

Muscles of

Lacrimal and

palpebral, corneal,

x

Meninges

V - Trigeminal

sensory from

*3 branches*

Trigeminal

Sensation

mastication

salivary glands

masticatory muscle

mastication

face and

V1 Opthalmic

ganglion

mass/movement

oral cavity

V2 Maxillary

V3 Mandibular

Medial strabismus,

Exits via orbital

x

Extraocular

VI - Abducens

Myelencephalon

Eye

external

x

x

x

fissure with CN

x

Synapses on

III, IV, & V1

movement

opthalmoparesis

Muscles

ocular muscles

Assessed with menace and

palpebral reflex assessments

Muscles of

Lacrimal, nasal,

Myelencephalor

Passes through

Ear sensation;

Facial

Lacrimal and

Damage can cause

Medulla oblongata

taste

expression

salivary glands

salivary glands

Part of

Taste

VII Facial

sytlomastoid

neurogenic

facial

foramen and

keratoconjunctivitis sicca &

ear

courses very

lack of sensation to pinnae

through ear

expression

shallow to skin

Myelencephalon

Does not leave skull,

Vestibular

x

*Hearing,

x

VIII -

originates in inner

Hearing &

x

ataxia,

X

vestibular

x

Lateral aspect of

ear via internal

Vestibulocochlear

medulla oblongata

acoustic meatus

Balance

deafness

sense*

Gag reflex,

one

Caudal

Myelencephalon

Passes

Pharynx,

Throat

Throat

Salivary

IX

through

muscles

glands

dysphagia

pharyngeal

Salivary

Lateral aspect

oral

middle

Glossopharyngeal

sensation

of medulla

jugular

muscle

glands

cavity

ear, Taste

oblongata

foramen

Gag reflex,

Larynx,

Longest; passes

Internal organ

Internal

Smooth muscle

Muscles

Visceral,

Myelencephalon

External

x vagus

through jugular

and glands of

dysphagia,

sensation,

of throat

muscle and

pharynx,

lateral aspect

organ muscle

laryngeal

ear canal

foramen

taste

contraction

neck, thorax,

dysfunction

glands

meninges,

of medulla

abdomen

taste

oblongata

spinal roots pass

shoulder/

Myelencephalon

Movement

x

Neck

x

x

XI spinal

through Foramen

x

neck muscle

x

Does not

magnum; exits

of head &

muscles

Accessory

innervate head

via jugular

neck

tone & mass

foramen

Runs lateral to

Tongue

x

XII - Hypoglossal

Myelencephalon

Tongue

Tongue

x

x

ext. carotid

x

x

movement

Ventral aspect

artery with

movement

muscles

of medulla

linguofacial

/atrophy

oblongata

trunk