Cranial Nerves

Question 1

CN is responsible for 5 special senses:

Answer 1

taste
vision
hearing
smell
balance

Question 2

CN I:
S or M:
Function:
Test:

Answer 2

Olfactory N.
Sensory
Smell
place scent under nostril - test each nostril separately

Question 3

CN II:
S or M:
Function:
Test:

Answer 3

Optic N.
Sensory
Vision
Snellen chart/light reflex

Question 4

CN III:
S or M:
Function:
Test:

Answer 4

Oculomotor N.
Motor
Constricts pupil
H-test/light reflex

Question 5

CN IV:
S or M:
Function:
Test:

Answer 5

Trochlear N.
Motor
Eyes movement
H-Test

Question 6

CN V:
S or M:
Function:
Test:

Answer 6

Trigeminal N. (V1, V2, V3)
Sensory & Motor
Mastication of the face muscle
Feel the face for sensory components

Question 7

CN VI:
S or M:
Function:
Test:

Answer 7

Abducens N.
Motor
Lateral eyes movement
H-Test

Question 8

CN VII:
S or M:
Function:
Test:

Answer 8

Facial N.
Sensory & Motor
Taste of tongue/muscles of face
Smile

Question 9

CN VIII:
S or M:
Function:
Test:

Answer 9

Vestibulochoclear N.
Sensory
Head position, sound, equilibrium
Fingertip rub

Question 10

CN IX:
S or M:
Function:
Test:

Answer 10

Glossopharyngeal N.
Sensory & Motor
touch & taste of tongue (pos. 2/3)
Gag reflex/post. tongue taste

Question 11

CN X:
S or M:
Function:
Test:

Answer 11

Vagus N.
Sensory & Motor
Throat & visceral mm.
Phonation “ahh”/ gag reflex

Question 12

CN XI:
S or M:
Function:
Test:

Answer 12

Accessory N.
Motor only
SCM and Trap
resisted shoulder shrug

Question 13

CN XII:
S or M:
Function:
Test:

Answer 13

Hypoglossal N.
Motor
ipsilateral tongue m.
Stick out tongue

Question 14

what is the cause of Bell’s palsy?

Answer 14

injury to CN VII producing paralysis of some or all facial muscles on the affected side

Question 15

CN VII is vulnerable to compression when ________

Answer 15

a viral infection produces inflammation

Question 16

in a healthy individual, if you shine a light in one eye, which eye(s) will constrict?

Answer 16

both

Question 17

which CNs are involved with pupillary light reflex?

Answer 17

II (afferent, sensory)
III (efferent, motor)

Question 18

a nerve that sends a signal toward the CNS / away from the stimulus

Answer 18

afferent

Question 19

a nerve that sends a signal from the CNS toward muscles, organs

Answer 19

efferent

Question 20

if you shine light into the R eye and it constricts but the L eye does not constict, what is the problem?

Answer 20

CN III on R works
CN IIII on L does not work

Question 21

if you shine light in L eye and R eye constricts but L does not, what is the problem?

Answer 21

CN III left