Cranial Nerves (9-12 not included)

trigeminal neuralgia

intense face pain

number of cranial nerves in body

24 (12 from R, 12 from L brain)

nerves define

bundled axonal extensions

transmit electric impulse to (afferent/sensory) & from (efferent/motor) brain + SC

nerves

peripheral (cranial & spinal nerves)

tracts

central (in brain & SC)

mixed nerves

sensory + motor

dorsal root

sensory

ventral root

motor

epineurium

cover peripheral nerve

perineurium

around one fascicle

endoneurium

cover each axon

__nerium in order

epineurium → perineurium → endoneurium

uncus

olfactory center of brain (“there’s a skunkus in my uncus”)

smell is only sense that bypass hypothalamus → goes straight to uncus

cranial nerves that attach to forebrain

first 2 pairs

cranial nerves that attach to brainstem

remaining 10 pairs

nerve I

olfactory n.

olfactory n.

sensory

sense of smell

olfactory n. clinical test

ask person to identify odor (can you smell anything? what do you smell?)

anosmia

lack of smell

nerve II

optic n.

optic n.

sensory

vision

extension of brain = covered in all 3 meningeal layers

optic n. clinical test

snellen eye chart

order for vision

retina → optic nerve → canal → chiasm → tract → thalamus → radiations → visual cortex

nerve III

oculomotor n.

oculomotor n.

motor

eyeball mvmt

innervates FOUR extraocular eye musc (superior rectus, inferior rectus, medial rectus, inferior oblique)

pupillary constrict in bright light (miosis)

lens accommodation/focusing

oculomotor n. clinical test

field of gaze

superior rectus

pull eye up

inferior rectus

eye to down

medial rectus

eye to midline

inferior oblique

look up & away

extraocular muscles innervated by nerve III

superior rectus

inferior rectus

medial rectus

inferior oblique

nerve IV

trochlear n.

trochelar n.

motor

mvmt of ONE eye musc (superior oblique)

smallest & longest cranial nerve

superior oblique

look down & away (cheating musc)

nerve V

trigeminal n.

trigeminal n.

mixed

sensory to face

control musc of mastication (temporalis, masseter, medial & lateral pterygoids)

largest cranial nerve

3 divisions

trigeminal n. V1 - ophthalmic division

sensation from forehead/eyelids/nose

LISSE

lacrimal n.

infratrochlear n.

supraorbital n.

supratrochlear n.

external nasal n.

trigeminal n. V2 - maxillary division

sensation from lower eyelid/upper lip/cheek

ZIZ

zygomaticofacial n.

infraorbital n.

zygomaticotemporal n.

trigeminal n. V3 - mandibular division

control mastication

BAM

buccal

auriculotemporal

mental

nerve VI

abducens

abducens

motor

move eyeball laterally (abduct = take away from midline)

innervate lateral rectus

lateral rectus

eye to side

weakness in lateral rectus (lazy eye)

treatment for L eye → eye patch on R eye

nerve VII

facial n.

facial n.

mixed

control musc of facial expression

control lacrimal, submandibular, sublingual salivary glands

taste anterior 2/3 of tongue (sweet, salty, sour)

branches of facial n.

Two Zebras Bit My Coccyx

Temporal

Zygomatic

Buccal

Mandibular

Cervical

Posterior Auricular

nerve VIII

vestibulocochlear n.

vestibulocochlear n.

sensory

vestibulo → equilbrium/balance

cochlear → hearing

travel thru internal acoustic meatus

3 cranial nerves that help move eyeball

nerve III, IV, VI (oculomotor, trochlear, abducens)

LR6 SO4 / 3

lateral rectus → nerve 6 (abducens)

superior oblique → nerve 4 (trochlear)

remaining (superior rectus, inferior rectus, medial rectus, inferior oblique) → nerve 3 (oculomotor)

Oh Oh Oh To Touch And Feel Very Green Vegetables - AH

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Olfactory (s), Optic (s), Oculomotor (m), Trochlear (m), Trigeminal (b), Abducens (m), Facial (b), Vestibulocochlear (s), Glossopharyngeal (b), Vagus (b), Accessory (m), Hypoglossal (m)