Cranial Nerve Functions

6. Abducens

Carries somatic motor fibers to lateral rectus muscle that moves the eyeball.

12. Hypoglossal

Mixed (but primarily motor in function) - carries somatic motor fibers to muscles of tongue.

11. Accessory

Mixed (but primarily motor in function) - provides somatic motor fibers to sternocleidomastoid and trapezius muscles and to muscles of soft palate, pharynx, and larynx (spinal and medullary fibers respectively).

10. Vagus

Mixed - fibers carry somatic motor impulses to pharynx and larynx and sensory fibers from same structures; very large portion is composed of parasympathetic motor fibers, which supply heart and smooth muscles of abdominal visceral organs; transmits sensory impulses from viscera.

5. Trigeminal

Mixed - major sensory nerve of face; conducts sensory impulses from skin of face and anterior scalp, from mucosae of mouth and nose, and from surface of eyes; mandibular division also contains motor fibers that innervate muscles of mastication and muscles of floor of mouth.

9. Glossopharyngeal

Mixed - somatic motor fibers serve pharyngeal muscles, and parasympathetic motor fibers serve salivary glands; sensory fibers carry impulses from pharynx, tonsils, posterior tongue (taste buds), and from chemoreceptors and pressure receptors of carotid artery.

7. Facial

Mixed - supplies somatic motor fibers to muscles of facial expression and parasympathetic motor fibers to lacrimal and salivary glands; carries sensory fibers form taste receptors of anterior portion of tongue.

4. Trochlear

Primarily motor - provides somatic motor fibers to superior oblique muscle that moves the eyeball.

3. Oculomotor

Primarily motor- somatic motor fibers to inferior oblique and superior, inferior, and medial rectus muscles, which direct eyeball, and to levator palpebrae muscles of the superior eyelid; parasympathetic fibers to iris and smooth muscle controlling lens shape (reflex responses to varying light intensity and focusing of eye for near vision).

1. Olfactory

Purely sensory - carries afferent impulses associated with sense of smell

2. Optic

Purely sensory - carries afferent impulses associated with vision.

8. Vestibulocochlear

Purely sensory - vestibular branch transmits impulses associated with sense of equilibrium from vestibular apparatus and semicircular canals; cochlear branch transmits impulses associated with hearing from cochlea