Unit 1: 12 Cranial Nerves

Question 1

12 Cranial Nerves

Answer 1

• Olfactory Nerve (CN I)
• Optic Nerve (CN II)
• Oculomotor Nerve (CN III)
• Trochlear Nerve (CN IV)
• Trigeminal Nerve (CN V)
• Abducens (CN VI)
• Facial Nerve (CN VII)
• Vestibulocochlear Nerve(CN VIII) (Acoustic)
• Glossopharyngeal (CN IX)
• Vagus Nerve (CN X)
• Spinal Accessory Nerve (CN XI)
• Hypoglossal Nerve (CN XII)

Question 2

Olfactory Nerve (CN I)

Answer 2

located in the nose
>Function:
-controls sense of smell
>Assessment: 
-identify odors with each nares separately

Question 3

Optic Nerve (CN II)

Answer 3

located in and behind the eyes; retina
>Function:
-controls central and peripheral vision; visual fields
-use Snellen chart
>Assessment:
-examine ocular fundus with ophthalmoscope
-assess light reflex

Question 4

Oculomotor Nerve (CN III)

Answer 4

positioned in and behind the eyes; pupil
>Function: 
-controls pupillary constriction
-extraocular eye movement
-elevation of eyelid
>Assessment: 
-assess EOM with 6 cardinal positions of gaze (make X and then horizontal line across it)
-cover/ uncover test 
-assess constriction with light

Question 5

Trochlear Nerve (CN IV)

Answer 5

(From picture pneumonic) 
>Function: 
-acts as a pulley to move eyes down- toward the tip of the nose
-extraocular eye movements
>Assessment: same as CN III
-move finger up and down

Question 6

Trigeminal Nerve (CN V)

Answer 6

covers most of the face
-if problem with the nerve, it usually involves forehead, cheek, or jaw
>Function:
-somatic sensations of cornea and face (corneal reflex)
-somatic sensations of face, oral cavity, anterior 2/3 of tongue, teeth (clenching jaw)
-somatic sensation lower face
-mastication (chewing)
>Assessment:
-palpate temporal and masseter muscles teeth clenched
-test corneal reflex, touch forehead, cheeks, and chin with cotton wisp
-symmetrical comparisons
-bite down or chew
-check sensation in all 3 areas using a soft and a dull object

Question 7

Abduces (CN VI)

Answer 7

lateral eye movement
>Function:
-controls eye movement to the sides
>Assessment:
-look to "right and left"

Question 8

Facial Nerve (CN VII)

Answer 8

>Function
-controls facial movement and expression
-salivation
>Assessment:
-assess for facial symmetry
-smile
-frown
-puff cheeks
-wrinkle forehead
-show his teeth
-when smiles, observe nasolabial folds for weakness or flattening

Question 9

Vestibulocochlear (CN VIII)/ (Acoustic)

Answer 9

located in the ears
>Function:
-controls hearing
-equilibrium
>Assessment:
-rub fingers together by each ear
-hearing acuity

Question 10

Glossopharyngeal (CN IX)

Answer 10

innervates the tongue and throat
>Function:
-taste
-swallowing
>Assessment: (along with CN X and XII)
-uvula symmetry
-identifies taste
-test gag reflex, use tongue blade, note rise of uvula with "ahh"
-observe ability to swallow by noting how they handle secretions

Question 11

Vagus Nerve (CN X)

Answer 11

innervates the tongue and throat
>Function:
-swallowing
-sensation in pharynx, larynx
>Assessment: (along with CN IX and XII); same as CN IX
-uvula symmetry
-test gag reflex, use tongue blade, note rise of uvula with “ahh”
-observe ability to swallow by noting how they handle secretions

Question 12

Spinal Accessory Nerve (CN XI)

Answer 12

> Function:
-controls neck and shoulder movement
Assessment:
-shrug shoulders
-raise shoulders against hands to assess the trapezius muscle
-turn head/ push chin against hand to assess sternocleidomastoid muscle

Question 13

Hypoglossal Nerve (CN XII)

Answer 13

innervates the tongue
>Function:
-tongue movement
>Assessment: (check with CN IX (9) and CN X (10))
-move tongue side to side against a tongue depressor
-stick out tongue; midline
-look for problems with eating, swallowing, or speaking