Cranial Nerves

Front 1

CN I

Back 1

Olfactory Nerve

Special Sensory

Fibers pass through cribiform plate of ethmoid bone, surrounded by dura and arachnoid.

Synapse with mitral cells in olfactory bulb. Axons form olfactory tract to brain.

Bulbs and tracts technically anterior extensions of forebrain.

Front 2

CN II

Back 2

Optic

Special Sensory

Travels through optic canal

Front 3

CN III (Somatic portion)

Back 3

Oculomotor

Somatic Motor

Nerve cell bodies in midbrain

Exits superior orbital fissure

Motor to SR, IR, MR, IO, levator palpebrae superioris muscles.

Raises eyelid, turns eyeball up, down, medially

Front 4

CN III (Visceral portion)

Back 4

Oculomotor

Visceral motor

Presynaptic cell bodies in midbrain, synapse in ciliary ganglion

Travel through superior orbital fissure

Parasympathetic innervation to sphincter of pupil and ciliary muscle. Constricts pupil, accomodates lens of eye.

Front 5

CN IV

Back 5

Trochlear

Somatic motor

Cell bodies in midbrain

Travels through Superior orbital fissure

Motor to SO.

Assists in turning eye down and out, or down when ADducted.

Front 6

CN V1

Back 6

Ophthalmic branch of trigeminal nerve

General sensory

Cell bodies in trigeminal ganglion

Travels through superior orbital fissure.

Sensation from cornea, skin of forehead, scalp and nose, mucosa of nasal cavity and paransal sinuses.

Front 7

CN V2

Back 7

Maxillary brance of trigeminal

General sensory

Cell bodies lie in trigeminal ganglion

Travels through foramen rotundum

Sensation from skin of face over maxilla, including upper lip, maxillary teeth, mucosa of nose, maxillary sinuses, palate.

Front 8

CN V3 (Sensory portion)

Back 8

Mandibular branch from trigeminal

General sensory

Cell bodies lie in trigeminal ganglion

Travels through foramen ovale

Sensation from skin over mandible, side of head, mandibular teeth, tmj, muscosa of mouth, anterior 2/3 of tongue

Front 9

CN V3 (Motor)

Back 9

Mandibular nerve

Branchial Motor

Cell bodies lie in pons

Travel through foramen ovale

Motor to muscles of mastication, mylohyoid, anterior belly of digastric, tensor palatini, tensor tympani

Front 10

CN VI

Back 10

Abducent Nerve

Somatic motor

Cell bodies like in pons

Passes through superior orbital fissure

Motor to lateral rectus, turns eye laterally

Front 11

CN VIII (Vestibular)

Back 11

Vestibular branch of vestibulococheal nerve

Special sensory

Cell bodies like in vestibular ganglion

Exits through internal acoustic meatus

Vestibular sensation from semicircular ducts, utricle, and saccule related to position and movement of the head

Front 12

CN VIII (Cochlear)

Back 12

Cochlear branch of Vestibulocochlear nerve

Special sensory

Cells bodies lie in spiral ganglion

Exit through internal acoustic meatus

Hearing from spiral organ

Front 13

CN IX Components

Back 13

Branchial motor, Visceral motor, visceral sensory, special sensory, general sensory

Front 14

CN IX exits through?

Back 14

Jugular foramen

Front 15

CN IX Branchial motor

Back 15

Cell bodies lie in Medulla

Motor to stylopharyngeus to assist with swallowing

Front 16

CN IX Visceral motor

Back 16

Presynaptic: Medulla

Postsynaptic: Otic ganglion

Parasympathetic to parotid gland

Front 17

CN IX Visceral sensory

Back 17

Cell bodies lie in superior ganglion

Visceral sensation from parotid gland, carotid body and sinus, pharynx, middle ear

Front 18

CN IX Special sensory

Back 18

Cell bodies lie in inferior glangion

Taste from posterior 1/3 of tongue

Front 19

CN IX General sensory

Back 19

Cell bodies lie in inferior ganglion

Cutaneous sensation from external ear

Front 20

CN X Components

Back 20

Vagus Nerve

Branchial motor, visceral motor, visceral sensory, special sensory, general sensory

All exit via jugular foramen

Front 21

CN X Branchial Motor

Back 21

Cell bodies lie in medulla

Motor to constrictor muscles of pharynx (except for stylopharyngeus), intrinsic muscles of larynx, muscles of palate (except tensor veli palatini), and voluntary muscle in upper 2/3 of espophagus

Front 22

CN X Visceral Motor

Back 22

Presynaptic: Medulla
Postsynaptic: Nuerons near viscera

Parasympathetic innervation to smooth muscle of trachea, bronchi, digestive tract and cardiac muscle of heart

Front 23

CN X Visceral Sensory

Back 23

Cell bodies lie in inferior ganglion

Taste from epiglottis and palate

Front 24

CN X General Sensory

Back 24

Cell bodies lie in superior ganglion

Sensation from auricle, external acoustic meatus, dura mater of posterior cranial fossa

Front 25

CN XI

Back 25

Spinal Accessory nerve

Somatic Motor

Cell bodies lie in spinal cord

Exits via Jugular foramen

Motor to scm and trapezius

Front 26

CN XII

Back 26

Hypoglossal Nerve

Somatic motor

Cell bodies lie in medulla

Exit via hypoglossal canal

Motor to intrinsic and extrinsic muscles of tongue (except palatogossus)

Front 27

CN VII Pre Parotid Gland

Back 27

Facial Nerve

Motor nerve to all facial muscles.

Enters internal auditory meatus with CN VIII. Emerges on base of skull via stylomastoid foramen.

Two small branches as it emmerges: Posterior auricular nerve (innervates occipatalis and auricular muscles)

Nerve to stylohyoid and digastric muscles – muscles of the neck, not facial muscles

Front 28

CN VII Five Branches from Parotid Gland

Back 28

Sinks in Parotid Gland.
Five Terminal Branchs:

Temporal (frontalis and superior part of orbicularis oculi)

Zygomatic branches (cross zygomatic arch, innervates lower part of orbicularis oculi and zygomatic muscles)

Buccal (run superficial to masseter muscle, go to oral area and innervate buccinator and orbicularis oris)

Marginal mandibular branches (run along margin of mandible, innervate muscles of lower lip and chin)

Cervical branch (platysma)

Front 29

CN VII Branches Within the Facial Canal

Back 29

In Order:

Greater Petrosal Nerve (presynaptic parasympathetic fibers that ultimately supply the lacrimal gland, in the orbit)

Nerve to Stapedius (Tiny muscle in the inner ear that functions keeps the stapes from moving to much and protects your ears from sudden loud sounds, in a reflex fashion. Paralysis will lead to hyperacousis, sensitivity to loud sounds.

Chorda tympani nerve (Carries taste fibers from the anterior 2/3rd of the tongue and runs back to brain the same way) Sided.

Front 30

Which branch of V has motor fibers?

Back 30

Only the mandibular (V3) branch.

Special Visceral Efferent fibers that supply the four muscles of mastication.

Front 31

Trigeminal Nerve Ganglion

Back 31

Lies in middle cranial fossa. Contains cell bodies of pseudounipolar neurons and is strictly a sensory ganglion.

Front 32

Which areas of the skin does V1 innervate?

Back 32

Kkin of forehead, upper eye lid and dorsum, some of the sides, and tip of nose.

Front 33

Which areas of the skin does V2 innervate?

Back 33

Lower eyelid, upper lip, side of nose and area in front of temple.

Front 34

Which areas of the skin does V3 innervate?

Back 34

Reverse L shaped region, lower lip, chin, lower part of the cheek, part of ear, auricle, and temple.

Front 35

What area of facial skin does the trigeminal nerve NOT innervate?

Back 35

Only the angle of the mandible.