Cranial Nerves

olfactory (CN I- function)

function is sensory

smell from nasal mucosa of roof of each nasal cavity and superior sides of nasal septum and superior concha

aka smell

Optic (CN II-function)

function is sensory

vision from retina

oculomotor (CN III- function)

function is motor

motor to superior rectus, inferior rectus, medial rectus, inferior oblique, and levator palpebrae superioris muscles; raises superior eyelid; turns eyeball superiorly, inferiorly, and medially

trochlear (CN IV- function)

function is motor

motor to superior oblique to assist in turning eye inferolaterally (inferiorly when adducted)

trigeminal (CN V- types)

ophthalmic, maxillary, mandible

trigeminal ophthalmic (CN V1-function)

function is sensory

sensation from cornea, skin of forehead, scalp, eyelids, nose, and mucosa of nasal cavity, paranasal sinuses, and cranial dura

trigeminal maxillary (CN V2- function)

function is sensory

sensation from skin of face over maxilla, including upper lip, maxillary teeth, mucosa of nose, maxillary sinuses, palate, and cranial dura

trigeminal mandibular (CN V3-function)

function is both sensory and motor

sensory:

• sensation from skin over mandible, including lower lip, side of head, mandibular teeth, temporomandibular joint, mucosa of mouth, anterior 2/3 of tongue, and cranial dura

motor:

• motor to muscles of mastication, mylohyoid, anterior belly of digastric, tensor veli palatini, and tensor tympani

abducent (CN VI- function)

function is motor

motor to lateral rectus to turn eye laterally

facial (CN VII- function)

function is both sensory and motor

somatic sensory:

• sensation from skin of external acoustic meatus

special sensory:

• taste from anterior 2/3 of tongue and palate

somatic motor:

• motor to muscles of facial expression, and scalp; supplies stapedius of middle ear, stylohyoid, and posterior belly of digastric

visceral motor:

• parasympathetic innervation to submandibular and sublingual salivary glands, lacrimal gland, and glands of nose and palate

vestibulocochlear (CN VIII- function)

function is sensory

vestibular sensation from semicircular ducts, utricle, and saccule related to position and movement of head; hearing from spiral organ

glossopharyngeal (CN IX- function)

function is both sensory and motor

sensory:

• special: taste from posterior 1/3 of tongue and pharynx

• somatic: posterior 1/3 of tongue, fauces, naso- and oropharynx, auditory tube, and middle ear

• visceral: carotid body and sinus

motor:

• somatic: motor to stylopharyngeus to assist with swallowing

• visceral: parasympathetic innervation to parotid gland

vagus (CN X- function)

function is both sensory and motor

sensory:

• visceral: visceral sensation from base of tongue, pharynx, larynx, trachea, bronchi, heart, esophagus, stomach, and intestine

• special: taste from epiglottis and palate

• somatic: sensation from posterior auricle, tragus, external acoustic meatus, and dura mater of posterior cranial fossa

motor:

• somatic: motor to constritor muscles of pharynx (except stylopharyngeus); intrinsic muscles of larynx, muscles of palate (except tensor veli palatini), and striated muscle in superior 2/3 of esophagus

• visceral: parasympathetic innervation to smooth muscle of trachea, bronchi, digestive tract, and cardiac muscle of heart

Spinal accessory (CN XI- function)

function is motor

motor to sternocleidomastoid and trapezius

Hypoglossal (CN XII- function)

motor to intrinsic and extrinsic muscles of tongue (except palatoglossus)

olfactory (cranial exit)

foramina in cribiform plate of ethmoid bone

optic (cranial exit)

optic canal

superior orbital fissure

oculomotor, trigeminal ophthalmic, trochlear, abducent all exit through cranial exit…

trigeminal maxillary (cranial exit)

foramen rotundum

trigeminal mandibular (cranial exit)

foramen ovale

facial (cranial exit)

internal acoustic meatus; facial canal; stylomastoid foramen

vestibulocochlear (cranial exit)

internal acoustic meatus

jugular foramen

glossopharyngeal, vagus, and spinal accessory nerves all leave through cranial exit…

hypoglossal (cranial exit)

hypoglossal canal