CN I Olfactory
- Sensory function: sense of smell
- Origin: olfactory receptor cells
* Purely sensory

CN II Optic
- Sensory function: vision
- Origin: retina

CN III - Moves the eye.
- The levator palpebrae muscle helps open the eyelid.
Lr6SO4
- Lateral rectus: Cranial nerve 6
- Superior oblique: Cranial nerve 4
- Others: Cranial nerve 3
Somatic motor function: innervate four eye muscles that direct the eyeball
Visceral motor function: constrictor muscles of the iris constrict the pupil
- The medial rectus pulls the eye toward the midline.

CN IV Trochlear (Smallest cranial nerve)
- Somatic motor function: Innervate the superior oblique muscle
- The only cranial nerve with a dorsal point of attachment.
- Purely motor and innervates the superior oblique muscle.

CN V Trigeminal Nerves (longest)
Somatic motor function: mastication (chewing)
- 3 Part Section
- Opthalamic, maxilla, and mandibular
- The sensory portion is responsible for the face, touch, and temp.
- Cranial nerve #5 does not move the face; seven does.

CN VI Abducens Nerve
- Somatic motor function: Innervate the lateral rectus muscle.
- Lateral rectus - moves eyeball away
- Superior oblique (cranial nerve 4)
- Lateral rectus (cranial nerve 6)

CN VII Facial Nerve
- A mixed nerve: Chief somatic motor nerve to the facial nerves
- Taste information
- Cranial nerve #7 sends taste information for the 2/3 upper portion of the tongue
- 1/3 posterior of the tongue is innervated by nerve #9

• CN VIII: Vestibulocochlear Nerves

  • A 2 part nerve: vestibular and cochlear nerve

    • Conjoins into 1 whole nerve when it leaves the ear

  • Only sensory

    • Vestibular: equilibrium/balance

    • Cochlear: hearing

• CN IX: Glossopharyngeal

  • Mixed nerve

    • Sensory: Posterior ⅓ of tongue for taste

    • Motor: Swallowing

  • Glosso = tongue

  • Pharyngeal = throat/pharynx

• CN X: Vagus nerves

  • The LONGEST cranial nerve

  • The only one that innervates something outside the head or neck

    • This is done via the autonomic system

  • Mixed nerve

    • Sensory: Taste (from the epiglottis)

    • Motor: Swallowing and vocalization

      • Parasympathetically innervates thoracic and abdominal viscera

  • Laryngeal prominence = Adam’s apple

• CN XI: Accessory Nerves

  • Only motor

    • Innervates upper trap and sternocleidomastoid muscle

      • These are the main head/neck movement muscles

  • Originates from the cervical spinal cord and forms a nerve that goes through the foramen magnum

• CN XII: Hypoglossal

  • Innervate underneath the tongue

  • Only motor

    • Responsible for tongue motion, such as feeding, swallowing, and speech