Cranial Nerves

Question 1

Olfactory nerve

Answer 1

CN I
Function is smell
Test it one nostril at a time with non-noxious stimuli
Associated with the limbo system, certain smells deal with your emotions
Sensory
Comes off the brain

Question 2

Optic nerve

Answer 2

CN II
Function is vision
Rods and cones 
Retina has 5 layers of cells
Nerve, chiasm, tract 
Sensory
Comes off the brain

Question 3

Oculomotor nerve

Answer 3

CN III
Innervated superior, medial, and inferior rectus, inferior oblique, levator palpebrae superioris

Superior rectus moves eye up, medial moves eye in, inferior moves eye down
Inferior oblique does ocular rotation

Motor
Comes off midbrain

Question 4

Trochlear nerve

Answer 4

CN IV
Innervates superior oblique which does ocular rotation
Motor
Comes off midbrain

Question 5

Trigeminal nerve

Answer 5

CN V
Cutaneous branches that give sensation to the face: mandibular, maxillary, ophthalmic
Maxillary has alveolar branch, innervates teeth
Innervates muscles of mastication
Innervates TMJ
Both sensory and motor
Comes off pons

Question 6

Abducens nerve

Answer 6

CN VI
Innervates lateral rectus which moves eyeball out
Motor
Comes off pons

Question 7

Facial nerve

Answer 7

CN VII
Gives taste (sensory) to anterior 2/3 of tongue
Innervates all muscles of facial expression
Damage to this nerve leads to Bell’s palsy - face droops, treatment is steroids and exercises. Child has to see doctor
Both sensory and motor
Comes off pons

Question 8

Vestibulococohlear nerve

Answer 8

CN VIII
Functions in hearing and balance
Hearing mediated by cochlear
Balance mediated by utricle, saccule, and semicircular canals which deal with linear and rotatory movement
Balance depends on vision, proprioception, and the vestibular system
Sensory
Comes off medulla

Question 9

Glossopharyngeal nerve

Answer 9

CN IX
Sensation to posterior 1/3 of tongue 
Innervates two relay stations: carotid body and carotid sinus 
Also mediates gag reflex 
Both sensory and motor
Comes off medulla

Question 10

Vagus nerve

Answer 10

CN X
Chief parasympathetic nerve to the thorax and abdomen
Slows down heart rate
If you massage this bilateral you will cause someone to fall asleep
Travels in carotid sheath with jugular vein and the CCA
Will also elevate soft palate
Both sensory and motor
Comes off medulla

Question 11

Spinal accessory nerve

Answer 11

CN XI
Innervates sternocleidomastoid and trap
Motor
Comes off medulla

Question 12

Hypoglossal nerve

Answer 12

CN XII
Innervates all muscles of the tongue
Motor
Comes off medulla