Tom Eck – ecktw@umdnj.edu


Cranial nerves are tested directly or indirectly on the majority of questions

Know the course of each nerve, especially the foramen each passes through

Know cutaneous distribution for sensory nerves and muscles innervated for motor nerves

Memorize presentation of deficits associated with loss of each nerve


Cranial Nerves: Sensory

Cranial Nerves: Motor

Cranial Nerves: Autonomic

Vasculature

Neck

Lymphatics

Embryology

Connections


CN I – Olfactory – Olfaction

CN II – Optic – Vision

CN V – Trigeminal – Facial Sensation

CN VII – Facial – Taste

CN VIII – Vestibulocochlear – Balance, Hearing

CN IX – Glossopharyngeal – Pharyngeal Sensation

CN X – Vagus – Laryngeal Sensation

, Ophthalmic artery
Middle meningeal artery
,
Labyrinthine artery
,
Posterior meningeal artery

1. WHICH BONE, WHEN FRACTURED, MAY BE ASSOCIATED WITH
INABILITY TO SMELL (ANOSMIA) AS WELL AS LEAKAGE OF CSF?
1.
2.
3.
4.
5.
Nasal
Ethmoid
Vomer
Sphenoid
Lacrimal
90%
5%
N as al
Et hmo id
5%
0% 0%
V omer
Sp hen oi d
La cr ima l


May result in damage to
CN I fibers as they pass through the cribriform plate of the ethmoid

Ethmoid is particularly vulnerable to trauma

Also associated with
CSF leakage (CSF rhinorrhea)

Nasogastric
Tube

2. WHERE MIGHT TUMOR INVASION LEAD TO ANESTHESIA OVER THE UPPER
LIP, INFRAORBITAL REGION, AND TEMPORAL REGION?
1.
2.
3.
4.
5.
1
2
3
4
5
39%
53%
1
0%
2 3
4% 4%
4 5

2

Numbness in the upper lip, infraorbital region, and temporal region suggests the tumor has invaded the maxillary nerve (V
2
), which exits the skull via the foramen rotundum.

It becomes the infraorbital nerve as it exits the skull via the infraorbital foramen

You would also expect loss of sensation in the nasal mucosa and oral cavity

3. WHICH OF THE FOLLOWING NERVES DOES NOT CONTRIBUTE
TO THE CUTANEOUS INNERVATION OF THE EAR?
1.
2.
3.
4.
5.
Maxillary nerve (V
2
)
Mandibular nerve (V
3
)
Facial nerve (CN VII)
Glossopharyngeal nerve (CN IX)
Vagus nerve (CN X)
9% 9%
11%
28%
45%
Ma xil la ry
n er v.
..
nd ib ul ar
n er
...
Ma
Fa cia l n er ve
(..
.
G lo ss op ha ry ng e.
..
V ag us
n er ve
(C
...







Auriculotemporal nerve (CN V3)

Root, superior helix, crus, tragus, ext auditory canal, tympanic membrane
Auricular branch (CN VII)

Concha, ext auditory canal
Jacobsen’s nerve (CN IX)

Concha, ext auditory canal
Arnold’s nerve (CN X)

Concha, ext auditory canal, antihelix
Lesser occipital nerve (C2)

Superoposterior ear
Great auricular (C2,3)

Lateral helix, lobule, posteroinferior ear

4. WHAT NERVE HAS BEEN COMPROMISED IF A PATIENT
EXPERIENCES NUMBNESS OF THE ANTERIOR TONGUE?
1.
2.
3.
4.
5.
Chorda tympani
Lingual
Hypoglossal
Glossopharyngeal
Vagus
62%
19%
9%
6%
4%
C ho rd a t ymp an i
Li ng ua l
H yp ss al og lo
G lo ss op ha ry ng ea l
V ag us


Lingual nerve = sensation to anterior 2/3 of tongue

Chorda tympani = taste to anterior 2/3 of tongue

Hypoglossal = motor to intrinsic and extrinsic tongue muscles (except palatoglossus)

Glossopharyngeal = taste AND sensation to posterior 1/3 of tongue

Vagus = taste for small patch near epiglottis

5. WHICH OF THE FOLLOWING NERVES CARRIES
THE AFFERENT LIMB OF THE CORNEAL REFLEX?
1.
2.
3.
4.
5.
Ophthalmic
Maxillary
Facial
Occulomotor
Mandibular
67%
12%
19%
O ph th al mi c
Ma xil la ry
0%
2%
Fa cia l
O cc ul omo to r
Ma nd ib ul ar


Afferent Limb: Ophthalmic Nerve, V
1
(Nasociliary Branch)

Efferent Limb: Zygomatic Branch of Facial
Nerve (CN VII) to palpebral portion of orbicularis oculi

Remember : V
1 includes the eyes and the tip of the nose

6. WHICH NERVE SUPPLIES THE SKIN OVERLYING THE
VERTEX OF THE SKULL?
1.
2.
3.
4.
5.
Lacrimal
Supratrochlear
Infratrochlear
Infraorbital
Supraorbital
47%
53%
0% 0% 0%
La cr ima l
Su pr at ro ch lea r
In fra tro ch lea r
In fra or bi ta l
Su pr ao rb ita l

Vertex


Supplies much of the forehead and scalp
 a branch of the ophthalmic nerve (V
1
 frontal nerve  supraorbital)

Exits the skull via the supraorbital foramen

7. WHICH AREA OF THE FACE WOULD BE EXPECTED TO EXPERIENCE
ANESTHESIA FOLLOWING A FRACTURE OF THE BODY OF THE MANDIBLE?
1.
2.
3.
4.
5.
Angle of jaw
Lower lip
Upper lip
Buccal region
Zygomatic region
69%
18%
9%
4%
0%
A ng le of
ja w
Lo w er
lip
U pp er
lip
Bu cc al reg io n
Zy go ma tic
reg i..
.


 branches off the inferior alveolar nerve (V
3
), which courses through the mandible, supplying the skin of the chin (mental region) and lower lip exits the mandible via the mental foramen


CN III – Oculomotor

CN IV – Trochlear extraocular muscles

CN VI – Abducens

CN V
3
– Mandibular – muscles of mastication

CN VII – Facial – muscles of expression

CN IX – Glossopharyngeal – stylopharyngeus

CN X – Vagus – muscles of pharynx and larynx

CN XI – Spinal Accessory – trapezius, SCM

CN XII – Hypoglossal – tongue muscles

8. A POSTERIOR FOSSA TUMOR IMPINGES ON THE JUGULAR FORAMEN.
WHICH OF THE FOLLOWING WILL BE ENTIRELY PRESERVED?
1.
2.
3.
4.
5.
swallowing phonation chewing shrugging taste
62%
22%
2%
6%
8%
sw al lo w in g
p ho na tio n
ch ew in g
sh ru gg in g
ta st e







Jugular foramen: glossopharyngeal
(CN IX), vagus (X), spinal accessory
(CN XI)
Swallowing = vagus, glossopharyngeal, etc.
Phonation = vagus (laryngeal muscles)
Taste = vagus, glossopharyngeal,
(and facial)
Shrugging = spinal accessory, etc.
Chewing = mandibular nerve (V
3
)

9. WHICH OF THE FOLLOWING MOST DIRECTLY
OPPOSES THE ACTION OF THE TEMPORALIS?
1.
2.
3.
4.
Masseter
Infrahyoid muscles
Lateral pterygoid
Medial pterygoid 29%
52%
15%
4%
Ma ss et er
In fra hy oi d mu s..
.
La ter al pt er yg
...
Med ia l p ter yg o.
..








3
temporalis = elevate and retract the mandible lateral pterygoid = depress and protrude mandible
Temporalis
Elevation: Temporalis, Masseter, Medial
Pterygoid
Depression: Lateral Pterygoid, Suprahyoid/Infrahyoid
Muscles
Protrusion: Lateral Pterygoid, Masseter, Medial
Pterygoid Lateral
Retrusion: Temporalis, Masseter
Lateral Movements: Temporalis of Opposite Side, Masseter
Pterygoid of same side, Pterygoids

Remember: Unilateral V3 lesion causes deviation to same side as lesion due to unopposed action of the contralateral medial and lateral pterygoid

10. PATIENTS WITH PARALYSIS OF THE TRIGEMINAL NERVE
LOSE FUNCTION IN WHICH OF THE FOLLOWING MUSCLES?
1.
2.
3.
4.
5.
Levator veli palatini
Palatopharyngeus
Stylohyoid
Stylopharyngeus
Tensor veli palatini
19%
9%
15%
11%
47%
Lev at or
veli
p al at in i
P al at op ha ry ng eu s
St ylo hy oi d
St ylo ph s ar yn geu
T en so r v eli
p al at in i

3

Temporalis

Masseter

Lateral pterygoid

Medial pterygoid

Mylohyoid

Anterior belly of digastric

Tensor tympani

Tensor veli palatini

11. WHICH OF THE FOLLOWING DOMINATES THE
EFFERENT LIMB OF THE GAG REFLEX?
1.
2.
3.
4.
CN V
CN IX
CN X
CN XII
42%
47%
9%
C
N
V
2%
C
N
IX
C
N
X
C
N
XI
I


Th e nerve supply to the pharynx is derived from the pharyngeal plexus

Glossopharyngeal = sensory supply (afferent limb)

Vagus = motor supply (efferent limb)

Sensory Exceptions: upper nasopharynx supplied by V
2
(along with nasal mucosa); lower laryngopharynx supplied by internal laryngeal (CN X)

Motor Exceptions: stylopharyngeus (CN IX), tensor veli palatini (CN V
3
) *These are also involved in the reflex

12. WHICH NERVE IS DAMAGED IF A PERSON MUST
CONSTANTLY PRESS THEIR CHEEK IN WHILE EATING?
1.
2.
3.
4.
5.
CN V
CN VII
CN IX
CN X
CN XII
82%
18%
C
N
V
C
N
VI
I
C
N
IX
0% 0%
C
N
X
0%
C
N
XI
I

 innervated by the Facial Nerve
 keeps food out of the oral vestibule
 meets the superior pharyngeal constrictor
(CN X) posteriorly at the pterygomandibular raphe

13. WHICH OF THE FOLLOWING WOULD REMAIN FUNCTIONAL
FOLLOWING COMPRESSION OF THE COMMON TENDINOUS RING?
1.
2.
3.
4.
5.
Superior rectus
Lateral rectus
Superior Oblique
Sphincter pupillae
Dilator pupillae
50%
24%
18%
8%
0%
Su per io r r ec tu
...
La ter al rec tu s
Su per io r O bl iq
...
Sp hi nc ter
p up i..
.
D ila to r p up ill.
..



Through the common tendinous ring

OPTIC NERVE



Ophthalmic artery
Motor (Occulomotor n. , Abducens n.), except the
Trochlear nerve
Nasociliary nerve
Outside:



Opthalmic vein
Sensory (Lacrimal n., Frontal n.), except the nasociliary nerve (which supplies the eyeball)
Trochlear nerve

14. WHEN A PATIENT STICKS OUT HER TONGUE, IT DEVIATES TO
THE RIGHT SIDE. WHICH NERVE HAS BEEN DAMAGED?
1.
2.
3.
4.
Left glossopharyngeal
Right glossopharyngeal
Left hypoglossal
Right hypoglossal
31%
56%
4%
8%
Lef t g lo ss op ha ry ng ea l t g lo ss op
Ri gh ha ry ng ea l
Lef t h yp og lo ss al
Ri gh t h yp og lo ss al


Unilateral lesion causes the tongue to deviate to the SAME side when protruded

The intact genioglossus pulls the back of the tongue forward, deviating the tongue to the other side


COPS 3977 (Parasympathetic Ganglia)

C iliary = CN 3 (pupillary constriction and accomodation)

O tic = CN 9 (salivation)

P terygopalatine = CN 7 (lacrimation)

S ubmandibular = CN 7 (salivation)

Sympathetic fibers carried by arteries from superior cervical ganglion

15. A PATIENT COMPLAINS OF DRY EYES FOLLOWING TRAUMA. WHICH OF
THE FOLLOWING NERVES MAY HAVE BEEN DAMAGED AT ITS ORIGIN?
1.
2.
3.
4.
5.
Ophthalmic
Oculomotor
Long Ciliary
Facial
Maxillary
78%
12%
6%
0%
O ph th al mi c
O cu lo mo to r
Lo ng
C ili ar y
4%
Fa cia l
Ma xil la ry

PTERYGOPALATINE GANGLION

16. WHICH GANGLION IS LOCATED JUST BELOW THE FORAMEN OVALE
AND, WHEN DAMAGED, LEADS TO DRY MOUTH (XEROSTOMIA)?
4.
5.
6.
1.
2.
3.
Ciliary
Pterygopalatine
Otic
Submandibular
Geniculate
Trigeminal
(semilunar)
13%
39%
26%
20%
2%
0%
C ili ar y
P ter yg op al at in
...
O tic
Su bma nd ib ul ar
G en icu lat e
T rig emin al
(s e.
..

OTIC GANGLION

17. WHICH OF THE FOLLOWING NERVES CARRIES PRESYNAPTIC
PARASYMPATHETIC FIBERS TO THE SUBMANDIBULAR GLAND?
1.
2.
3.
4.
5.
Greater palatine
Lesser petrosal
Greater petrosal
Chorda tympani
Inferior alveolar
62%
16%
18%
4%
0%
G rea ter
p al at i..
.
Les ser
p et ro sa
...
G rea ter
p et ro s..
.
C ho rd a t ymp an i
In fer io r a lv eo
...

SUBMANDIBULAR
GANGLION

CILIARY GANGLION
Oculomotor Nerve (Pre)  Ciliary Ganglion  Short Ciliary Nerves (Post)



External Carotid and its branches

Anterior: superior thyroid, lingual, facial

Posterior: Occipital, Posterior Auricular

Medial: Ascending Pharyngeal

Terminal: Superfical Temporal, Maxillary
Internal Carotid and Circle of Willis

Dural Venous Sinuses

Basic Venous Drainage

Be familiar with major branches of maxillary, facial arteries

18. WHEN SIGNIFICANT TRAUMA IS INFLICTED AT THE PTERION, AN
EPIDURAL HEMATOMA OFTEN RESULTS. BY WHAT ROUTE DOES THE
INVOLVED ARTERY ENTER THE CRANIUM?
1.
2.
3.
4.
5.
Foramen ovale
Foramen rotundum
Foramen spinosum
Foramen lacerum
Sphenopalatine foramen
82%
6%
4% 4% 4% va le
o
Fo ra men
Fo ra men
ro tu nd um
Fo ra men um
sp in os
Fo ra men
la cer
Sp hen um op al at in e fo ra men



 pterion = major weak point in skull; location where the frontal, sphenoid, temporal, and parietal bones meet fracture here associated with laceration of underlying middle meningeal artery (responsible for 70-80% of epidural hematomas) enters the skull via the foramen spinosum

19. WHICH OF THE FOLLOWING DOES NOT TYPICALLY
BRANCH FROM THE INTERNAL CAROTID ARTERY?
2.
3.
1.
4.
5.
Anterior cerebral artery
Middle cerebral artery
Posterior cerebral artery
Posterior communicating artery
Ophthalmic artery
75%
19%
2% 2% 2%
A nt er io r c er eb
...
dd le cer
Mi eb ra
...
P os ter io r c er e.
..
P os ter io
..
r c omm.
O ph th al mi c a rt.
..


Represents a major site of anastomosis between the two vertebral arteries (via the basilar artery) and the two internal carotid arteries, which together supply the brain

20. WHICH OF THE FOLLOWING DRAINS BLOOD AWAY
FROM THE CONFLUENCE OF THE SINUSES?
3.
4.
5.
1.
2.
Transverse sinus
Superior sagittal sinus
Occipital sinus
Straight sinus
Sigmoid sinus
75%
8% 8%
10%
0%
T ra ns ver se sin
...
Su per io r s ag it.
..
O cc ip ita l s in u.
..
St ra ig ht
si nu s
Si gmo id
si nu s


Receives blood from the superior sagittal, straight, and occipital sinuses

Blood drains into the
(R/L) transverse sinuses, and from there to the (R/L) sigmoid sinuses


Fascial planes

Major vessels

Strap muscles – innervated by ansa cervicalis
(C1 to C5) * know segments contributed to each muscle

Larynx – structure, muscles, innervation

21. UPON SWALLOWING, WHAT HELPS TO ELEVATE THE
THYROID ALONG WITH THE TRACHEA AND LARYNX?
2.
3.
4.
1.
5.
Superficial
(investing) fascia
Prevertebral fascia
Pretracheal fascia
Suspensory ligaments
Pyramid lobe of the thyroid
42%
30%
18%
8%
2%
Su per fic ia l (i
...
P rev er teb ra l f
...
P ret ra ch ea l f a.
..
Su sp en so ry
lig
...
P yr ami d lo be o.
..




Superficial investing fascia



Suprahyoid muscles
SCM
Trapezius
Pretracheal fascia



Thyroid
Trachea
Move as a unit
Prevertebral fascia


Scalenes
Paravertebral muscles

22. BETWEEN WHICH STRUCTURES WOULD A PHARYNGEAL
INFECTION BE MOST LIKELY TO SPREAD TO THE MEDIASTINUM?
1.
2.
3.
4.
5.
Between the trachea and the carotid sheath
Between the trachea and the strap muscles
Between the trachea and the esophagus
Between the esophagus and the prevertebral muscles
Between the trapezius and the prevertebral muscles
20%
6%
20%
53%
0%
Bet w ee n th e t r..
.
Bet w ee n th e t r..
.
Bet w ee n th e t r..
.
...
Bet w ee n th e es
Bet w ee n th e t r..
.


Situated between the buccopharyngeal fascia and the alar fascia

Permits spread of infections into the mediastinum from the head and neck

23. WHICH OF THE FOLLOWING MUSCLES WOULD BE MOST ACTIVE IN
FORCED RESPIRATION, AS IN WHEN TAKING A DEEP BREATH?
1.
2.
3.
4.
5.
cricothyroid thyroarytenoid posterior cricoarytenoid lateral cricoarytenoid vocalis
35%
10%
37%
14%
4%
cr ico th yr oi d
th yr oa ry ten oi d
p os ter io r c ric
...
la ter al
cr ico a.
..
vo ca lis


Know actions of muscles (use names to give you clues)

Know motor innervation (all inferior laryngeal, except cricothyroid = external laryngeal)

Know sensory innervation

Superior to vocal ligament = internal laryngeal

Inferior to vocal ligament = inferior laryngeal (from recurrent laryngeal)


Expect 2 or 3 lymph questions

Lymph drainage of the face and tongue are key

Remember to keep an eye out for small details when studying

24. TO WHICH LYMPH NODES WOULD YOU EXPECT THIS
SQUAMOUS CELL CARCINOMA TO METASTASIZE FIRST?
1.
2.
3.
4.
5.
submental submandibular
Inferior jugular buccal parotid
98%
2%
su bmen ta l
su bma nd ib ul ar
In fer io r j ug ul ar
0% 0% 0%
b uc ca l
p ar ot id

 submental: central lower lip, chin, apex of tongue
 submandibular: upper lip, lateral lower lip, lateral part of anterior 2/3 of tongue

Inferior deep cervical: medial part of anterior
2/3

Superior deep cervical: posterior 1/3 of tongue

Parotid: lateral face and scalp, eyelids


Branchial Arches

Eye Development

Ear Development

Know the precursors

25. FROM WHICH OF THE BRANCHIAL ARCHES IS THE AFFECTED
NERVE DERIVED?
1.
2.
3.
4.
5.
First
Second
Third
Fourth
Fifth
66%
21%
Fi rs t
Sec on d
11%
2%
0%
T hi rd
Fo ur th
Fi fth

26. THE EXTERNAL AUDITORY MEATUS DEVELOPS FROM WHICH
OF THE FOLLOWING EMBRYOLOGIC STRUCTURES?
3.
4.
5.
1.
2.
First branchial arch
Second branchial arch
Third branchial arch
First branchial cleft
Second branchial pouch
57%
18%
11% 11%
2%
Fi rs t b ra nc hi a.
..
Sec on d br an ch i..
.
T hi rd
b ra nc hi a.
..
Fi rs t b ra nc hi a.
..
Sec on d br an ch i..
.

Arch Nerve
1 CN V
2 CN VII
3 CN IX
Skeletal
Structures
Mandible, malleus, incus, greater wing of sphenoid
Stylohyoid process,
stapes, upper body
& lesser horn of hyoid
Lower body & greater horn of hyoid
Muscles
Muscles of mastication, mylohyoid, anterior belly of digastric, tensor tympani, tensor veli palatini
Muscles of facial expression, stylohyoid, stapedius, postberior belly digastric
Stylopharyngeus
4
5-6
CN X
Superior laryngeal
CN X
Recurrent laryngeal
Thyroid cartilage
Cricoid cartilage
Cricothyroid, levator veli palatini, palatopharyngeus, palatoglossus, pharyngeal constrictors
Intrinsic muscles of larynx (except cricothyroid & stylopharyngeus)

27. THE SEMICIRCULAR CANALS DEVELOP FROM THE _________________ OF
THE OTIC VESICLE, WHICH IS ITSELF DERIVED FROM _______________.
3.
4.
1.
2.
Utricular part; surface ectoderm
Utricular part; neural ectoderm
Saccular part; surface ectoderm
Saccular part; neural ectoderm
15%
45%
23%
17%
U tri cu lar
p ar t..
.
U tri cu lar
p ar t..
.
Sa cc ul ar
p ar t;.
..
Sa cc ul ar
p ar t;.
..



 otic placode  otic pit  otic vesicle
Dorsal Utricular Part  utricle, semicircular canals (U looks like canals)
Ventral Saccular Part  saccule, cochlea (S for Spiral shape of cochlea)

 the cranium is a maze
 learn the major passageways
 especially true for the face

28. WHERE DO TEARS ENTER THE NASAL CAVITY?
1.
2.
3.
4.
5.
Inferior meatus
Middle meatus
Superior meatus
Sphenopalatine foramen
Pterygomaxillary fissure
58%
22%
2%
11%
7%
In fer io r mea tu s
Mi tu s tu s dd le mea
Su per io
Sp r mea op al at in e hen fo ra
P ter yg men oma xil la ry
fi ss ur e


Inferior meatus

Nasolacrimal duct

Middle meatus

Frontal sinus

Anterior ethmoidal air cells

Maxillary sinus

Superior meatus

Posterior ethmoidal air cells

Sphenoethmoidal recess

Sphenoidal sinus (associated with pituitary gland)

29. A TUMOR FROM THE INFRATEMPORAL FOSSA GAINS
ENTRANCE TO THE ORBIT. WHAT IS THE MOST LIKELY ROUTE?
3.
4.
1.
2.
5.
Superior orbital fissure
Inferior orbital fissure
Optic canal
Sphenopalatine foramen
Pterygoid canal
45%
22%
4%
12%
16%
Su per io r o rb it.
..
In fer io r o rb it.
..
O pt ic ca na l
Sp hen op al at in e.
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P ter yg oi d ca na
...

TO ORBIT
A tumor could also invade the nasal cavity by passing through the pterygomaxillary fissure and sphenopalatine foramen.


Be sure to spend some time with the models; there are a lot more on this exam

Be able to identify structures with the head in various positions

No mock practical this time, but use the structured lab review as a guide

HOW SOON BEFORE THE EXAM WOULD YOU LIKE THE REVIEW?
1.
2.
3.
Earlier
A week is good
Later
67%
25%
8%
Ea rli er
A
w ee k i s g oo d
La ter