Cranial Nerves

Question 1

Cranial nerves

Answer 1

1 - Olfactory n.
2 - Optic n.
3 - Oculomotor n.
4 - Trochlear n.
5 - Trigeminal n.
6 - Abducens n.
7 - Facial n.
8 - Vestibulocochlear n.
9 - Glossopharyngeal n.
10 - Vagus n.
11 - Spinal accessory n.
12 - Hypoglossal n.

Question 2

GSE

Answer 2

General somatic efferent

Somatic muscle.

Question 3

GVE

Answer 3

General visceral efferent

ANS to smooth and cardiac muscle and glands.

Question 4

SVE

Answer 4

Special visceral efferent

Supplies muscles derived from pharyngeal arches.

Question 5

GSA

Answer 5

General somatic afferent

Sensory in skin, joints, tendons, muscles (ectoderm).

Question 6

GVA

Answer 6

General visceral affarent

Sensory to visceral structures (endoderm)

Question 7

SSA

Answer 7

Special somatic afferent

Hearing, balance and sight.

Question 8

SVA

Answer 8

Special visceral afferent

Taste and smell.

Question 9

CN I
SS
Fibers
S/M/B
Exits via

Answer 9

Olfactory n.
SS - nasal cavity
Fibers - SVA
S/M/B - Sensory
Exits via - olfactory foramina of cribiform plate to olfactory bulb.

Question 10

Fx of the cribiform plate can cause:

Answer 10

CSF rhinorrhea

Question 11

How is CN I tested?

Answer 11

With several different odors.

Question 12

CN II
SS
Fibers
S/M/B
Exits via

Answer 12

SS - retina
Fibers - SSA
S/M/B - Sensory
Exits via - Optic canal

Question 13

Where does CN II terminate?

Answer 13

Geniculate bodies of thalamus

Question 14

Testing CN II

Answer 14

Light and dark testing
Finger counting
Snellen's test (80/20)
Visual field test
Peripheral vision test
Pupillary light reflex
Blink reflex

Question 15

CN III
SS
Fibers
S/M/B
Exits via

Answer 15

SS - motor to 4 extra-ocular ms. and PSNS to pupil and ciliary ms.
Fibers - GSE and GVE.
S/M/B - Motor
Exits via - Superior orbital fissure

Question 16

CN IV
SS
Fibers
S/M/B
Exits via

Answer 16

SS - motor to superior oblique m.
Fibers - GSE
S/M/B - Motor
Exits via - Superior orbital fissure

Question 17

CN VI
SS
Fibers
S/M/B
Exits via

Answer 17

SS - motor to lateral rectus m.
Fibers - GSE
S/M/B - Motor
Exits via - Superior orbital fissure

Question 18

Testing Levator palpebrae superioris m. (CN III)

Answer 18

Levator palpebrae superioris m. - hold forehead down and eyelid and have pt try to open.

Question 19

Testing superior rectus m. (CN III)

Answer 19

Abduct eye, then look up.

Question 20

Testing inferior rectus m. (CN III)

Answer 20

Abduct eye, then look down.

Question 21

Testing inferior oblique m. (CN III)

Answer 21

Adduct eye, then look up.

Question 22

Testing medial rectus m. (CN III)

Answer 22

Adduct eye.

Question 23

Check which muscle when testing CN IV

Answer 23

Superior oblique m.

Question 24

Check which muscle when testing CN VI

Answer 24

Lateral rectus m.

Question 25

``` CN V SS Fibers S/M/B Exits via ```

Answer 25

SS - sensation everywhere and motor to muscles of mastication. Fibers - GSA and SVE S/M/B - Both Exits via - V1 ophthalmic n. (S.O.F.), V2 maxillary n. (foramen rotundum) and V3 mandibular n. (foramen ovale)

Question 26

``` CN VII SS Fibers S/M/B Exits via ```

Answer 26

SS - motor to ms. of facial expression, PSNS to lacrimal, nasal and palatine glands, taste of anterior 2/3 of tongue and sensation to external acoustic meatus. Fibers - SVE, GVE, SVA, GSA S/M/B - Both Exits via - internal acoustic meatus and stylomastoid foramen.

Question 27

Testing of Facial n.

Answer 27

Sensation of tongue. Wrinkle forehead, blow whistle, smile, suck straw. Blink reflex Corneal reflex

Question 28

``` CN VIII SS Fibers S/M/B Exits via Divsions ```

Answer 28

``` SS - sense of hearing and equilibrium. Fibers - SSA S/M/B - Sensory Exits via - internal acoustic meatus Vestibular and cochlear division. ```

Question 29

Testing CN VIII - vestibular division (3)

Answer 29

Romberg's sign - balance, feet together, extend arms at sides, close eyes. Past pointing - finger to nose, w/ and w/o eyes open. Nystagmus - abnormal movement when eye scans the room.

Question 30

Testing CN VII - cochlear division (4)

Answer 30

Conduction deafness (wax, obstruction). Whispering/rubbing fingers. Rinne test Weber's test

Question 31

``` CN IX SS Fibers S/M/B Exits via ```

Answer 31

SS - sensation of ear and post 1/3 of tongue, sensory from oropharynx and carotid body, taste of post 1/3 of tongue, PSNS to post 1/3 of tongue, motor to stylopharyngeus ms. Fibers - GSA, GVA, SVA, GVE, SVE S/M/B - Both Exits via - jugular foramen

Question 32

CN IX is tested at same time as:

Answer 32

CN X

Question 33

``` CN X SS - tons Fibers S/M/B Exits via ```

Answer 33

SS - tons of stuff Fibers - SVA, GVA, GSA, GVE, SVA S/M/B - Both Exits via - jugular foramen

Question 34

``` CN XI SS Fibers S/M/B Exits via ```

Answer 34

SS - SCM m. and Trapezius m. Fibers - GSE S/M/B - Motor only Exits via - jugular foramen

Question 35

``` CN XII SS Fibers S/M/B Exits via ```

Answer 35

SS - tongue ms. Fibers - GSE S/M/B - Motor Exits via - hypoglossal canal

Question 36

Which nerves have GSE fibers?

Answer 36

CNs 3, 4, 6, 12

Question 37

Which nerves have GSA fibers?

Answer 37

CNs 3, 7, 9, 10

Question 38

Which nerves have SVE fibers?

Answer 38

CNs 5, 7, 9, 10

Question 39

Which nerves have SSA fibers?

Answer 39

CNs 2, 8