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Cranial Nerves
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1. Olfactory (I) – exits through cribriform plate (ethmoid bone)
a. special sensory for smell
2. Optic (II) – exits through optic foramen/canal (sphenoid bone)
a. special sensory for vision
3. Oculomotor (III) – exits through superior orbital fissure (sphenoid bone)
a. motor for most muscles of eyeball movements:
i. innervates superior, inferior, medial rectus muscles; inferior oblique muscle; levator
palpebrae superioris muscle
b. parasympathetic to sphincter of pupil and ciliary muscle of eye
4. Trochlear (IV) – exits through superior orbital fissure (sphenoid bone)
a. motor for one eye movement: innervates superior oblique muscle
5. Trigeminal (V)
a. Divisions: derived from the large Trigeminal Ganglion, found in middle cranial fossa
i. Ophthalmic – exits through superior orbital fissure (sphenoid bone)
1. general sensory from nasal cavity, skin of forehead, upper eyelid, external nose
ii. Maxillary – exits through foramen rotundum (sphenoid bone)
1. general sensory from lower eyelid, upper lip, gums, teeth and palate
iii. Mandibular branch – exits through foramen ovale (sphenoid bone)
1. general sensory from lower gums, teeth, lower lip, anterior 2/3 of tongue
2. somatic motor to muscles of mastication, anterior belly of digastric, mylohyoid,
tensor tympani, tensor veli palatini
iv. all the divisions have MANY branches that go on to supply specific muscles and regions of
the face and neck
6. Abducent/Abducens (VI) – exits through superior orbital fissure (sphenoid bone)
a. motor for one eye movement: innervates lateral rectus muscle
7. Facial (VII) – exits through internal acoustic meatus (temporal bone) and then stylomastoid foramen
(temporal bone)
a. mixed nerve: sensory and motor roots
i. special sensory for taste from anterior two-thirds of the tongue
ii. motor
1. (somatic) muscles of facial expression (including platysma, buccinator m); stapedius
m, posterior belly of digastric m, stylohyoid m
2. (parasympathetic) submandibular and sublingual salivary glands, lacrimal gland
(tears) and nasal mucous glands (snot)
8. Vestibulocochlear (Acousticovestibular) (VIII) – exits through internal acoustic meatus (temporal bone)
a. special sensory for balance and equilibrium (vestibular branch) and hearing (cochlear branch)
9. Glossopharyngeal (IX) – exits through jugular foramen (between temporal and occipital bones)
a. mixed nerve
i. general sensory and special sensory (taste) from posterior one-third of tongue; pharynx and
palate
ii. special sensory from carotid body (O2 level) and carotid sinus (blood pressure) of neck
iii. somatic motor to stylopharyngeus m. for swallowing
iv. parasympathetic motor to parotid gland
10. Vagus (X) – exits through jugular foramen (between temporal and occipital bones)
a. mixed nerve
i. sensory from
1. external ear, external auditory canal, epiglottis (taste)
2. visceral organs in thoracic and abdominopelvic cavities
ii. motor to
1. muscles of the palate (EXCEPT tensor veli palatini m.), pharynx, larynx;
2. parasympathetics to digestive, respiratory and cardiovascular systems in the thoracic
and abdominal cavities
b. travels from head to neck and down into thorax and abdomen
11. (Spinal) Accessory (XI) – exits through jugular foramen (between temporal and occipital bones)
a. motor to sternocleidomastoid and trapezius mm.
b. small cranial root (4-5 rootlets) and large spinal root (originates on spinal cord; travels through
foramen magnum to join cranial root)
12. Hypoglossal (XII) – exits through hypoglossal canal (occipital bone)
a. motor to muscles for tongue movements (EXCEPT palatoglossus m.)