HAD UNIT II CALM REVIEWTom Eck – ecktw@umdnj.edu

MAJOR POINTS 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

MAJOR TOPICS Cranial Nerves: Sensory Cranial Nerves: Motor Cranial Nerves: Autonomic Vasculature Neck Lymphatics Embryology Connections

CRANIAL NERVES: SENSORY 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

CRANIAL FORAMINA

, 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?

Nasal

Ethmoid

Vomer

Sphenoid

Lacri

mal

5%

90%

0%0%5%

1. Nasal2. Ethmoid3. Vomer4. Sphenoid 5. Lacrimal

ETHMOIDAL FRACTURE 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)

DON’T DO THIS!

NasogastricTube

1. 1 2. 23. 3 4. 45. 5

2. WHERE MIGHT TUMOR INVASION LEAD TO ANESTHESIA OVER THE UPPER LIP, INFRAORBITAL REGION, AND TEMPORAL REGION?

1 2 3 4 5

0%

39%

4%4%

53%

Numbness in the upper lip, infraorbital region, and temporal region suggests the tumor has invaded the maxillary nerve (V2), 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

MAXILLARY NERVE INJURY (V2)

3. WHICH OF THE FOLLOWING NERVES DOES NOT CONTRIBUTE TO THE CUTANEOUS INNERVATION OF THE EAR?

Maxil

lary nerv...

Mandibular n

er...

Facia

l nerve (..

.

Glossopharynge

...

Vagus nerve (C

...

9% 9%

45%

28%

11%

1. Maxillary nerve (V2)

2. Mandibular nerve (V3)

3. Facial nerve (CN VII)

4. Glossopharyngeal nerve (CN IX)

5. Vagus nerve (CN X)

CUTANEOUS INNERVATION OF EAR 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?

Chorda t

ympani

Lingu

al

Hypoglossa

l

Glossopharynge

al

Vagus

19%

62%

4%6%9%

1. Chorda tympani2. Lingual3. Hypoglossal4. Glossopharynge

al5. Vagus

TONGUE INNERVATION 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?

Ophthalmic

Maxil

lary Fa

cial

Occulomotor

Mandibular

67%

0% 2%

19%12%

1. Ophthalmic2. Maxillary3. Facial4. Occulomotor5. Mandibular

CORNEAL REFLEX Afferent Limb: Ophthalmic Nerve, V1

(Nasociliary Branch) Efferent Limb: Zygomatic Branch of

Facial Nerve (CN VII) to palpebral portion of orbicularis oculi

Remember: V1 includes the eyes and the tip of the nose

6. WHICH NERVE SUPPLIES THE SKIN OVERLYING THE VERTEX OF THE SKULL?

Lacri

mal

Supratro

chlear

Infra

troch

lear

Infra

orbital

Supraorbita

l

0%

47%53%

0%0%

1. Lacrimal2. Supratrochlear3. Infratrochlear4. Infraorbital5. Supraorbital

Vertex

SUPRAORBITAL NERVE Supplies much of the forehead and

scalp a branch of the ophthalmic nerve (V1

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?

Angle of ja

w

Lower li

p

Upper lip

Buccal re

gion

Zygo

matic regi...

9%

69%

0%

18%

4%

1. Angle of jaw2. Lower lip3. Upper lip4. Buccal region5. Zygomatic

region

MENTAL NERVE branches off the inferior alveolar nerve (V3), which

courses through the mandible, supplying the skin of the chin (mental region) and lower lip

exits the mandible via the mental foramen

CRANIAL NERVES: MOTOR CN III – Oculomotor CN IV – Trochlear extraocular muscles CN VI – Abducens CN V3 – 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?

swallo

wing

phonation

chewing

shrugg

ing ta

ste

2%6%

22%

8%

62%

1. swallowing2. phonation3. chewing4. shrugging5. taste

JUGULAR FORAMEN SYNDROME 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 (V3)

9. WHICH OF THE FOLLOWING MOST DIRECTLY OPPOSES THE ACTION OF THE TEMPORALIS?

Masse

ter

Infra

hyoid m

us...

Lateral

pteryg...

Medial p

terygo...

29%

4%

52%

15%

1. Masseter2. Infrahyoid

muscles3. Lateral

pterygoid4. Medial pterygoid

MUSCLES OF MASTICATION (V3) temporalis = elevate and retract the mandible lateral pterygoid = depress and protrude mandible

Elevation: Temporalis, Masseter, Medial Pterygoid

Depression: Lateral Pterygoid, Suprahyoid/Infrahyoid Muscles

Protrusion: Lateral Pterygoid, Masseter, Medial Pterygoid

Retrusion: Temporalis, Masseter Lateral Movements: Temporalis of same side,

Pterygoids of Opposite Side, Masseter

Remember: Unilateral V3 lesion causes deviation to same side as lesion due to unopposed action of the contralateral medial and lateral pterygoid

Temporalis

Lateral Pterygoid

10. PATIENTS WITH PARALYSIS OF THE TRIGEMINAL NERVE LOSE FUNCTION IN WHICH OF THE FOLLOWING MUSCLES?

Levator v

eli palatini

Palatopharynge

us

Stylo

hyoid

Stylo

pharynge

us

Tensor v

eli palatini

19%

9%

47%

11%15%

1. Levator veli palatini

2. Palatopharyngeus

3. Stylohyoid4. Stylopharyngeu

s5. Tensor veli

palatini

CN V3 - MANDIBULAR NERVE (MOTOR)

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?

CN V CN IX

CN X CN XII

2%

9%

47%42%

1. CN V2. CN IX3. CN X4. CN XII

GAG REFLEX The 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 V2 (along with nasal mucosa); lower laryngopharynx supplied by internal laryngeal (CN X)

Motor Exceptions: stylopharyngeus (CN IX), tensor veli palatini (CN V3) *These are also involved in the reflex

12. WHICH NERVE IS DAMAGED IF A PERSON MUST CONSTANTLY PRESS THEIR CHEEK IN WHILE EATING?

CN V CN VII

CN IX CN X

CN XII

18%

82%

0%0%0%

1. CN V2. CN VII3. CN IX4. CN X5. CN XII

BUCCINATOR 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?

Superio

r rectu

...

Lateral

rectu

s

Superio

r Obliq

...

Sphincte

r pupi...

Dilato

r pupill.

..

0%

8%

18%24%

50%1. Superior rectus2. Lateral rectus3. Superior Oblique4. Sphincter

pupillae5. Dilator pupillae

COMMON TENDINOUS RING 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

Left gl

ossopharyn

geal

Right g

lossophary

ngeal

Left hypoglossa

l

Right h

ypoglossal

4%

56%

31%

8%

14. WHEN A PATIENT STICKS OUT HER TONGUE, IT DEVIATES TO THE RIGHT SIDE. WHICH NERVE HAS BEEN DAMAGED?

1. Left glossopharyngeal

2. Right glossopharyngeal

3. Left hypoglossal4. Right hypoglossal

HYPOGLOSSAL NERVE 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

CRANIAL NERVES: AUTONOMICS COPS 3977 (Parasympathetic Ganglia) Ciliary = CN 3 (pupillary constriction

and accomodation) Otic = CN 9 (salivation) Pterygopalatine = CN 7 (lacrimation) Submandibular = 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?

Ophthalmic

Oculomotor

Long C

iliary

Facia

l

Maxil

lary

0%6% 4%

78%

12%

1. Ophthalmic2. Oculomotor3. Long Ciliary4. Facial5. Maxillary

PTERYGOPALATINE GANGLION

16. WHICH GANGLION IS LOCATED JUST BELOW THE FORAMEN OVALE AND, WHEN DAMAGED, LEADS TO DRY MOUTH (XEROSTOMIA)?

Ciliary

Pterygopalatin...

Otic

Submandibular

Geniculat

e

Trigeminal (s

e...

0%

13%

2%

20%

26%

39%1. Ciliary2. Pterygopalatine3. Otic4. Submandibular5. Geniculate6. Trigeminal

(semilunar)

OTIC GANGLION

17. WHICH OF THE FOLLOWING NERVES CARRIES PRESYNAPTIC PARASYMPATHETIC FIBERS TO THE SUBMANDIBULAR GLAND?

Greater p

alati...

Lesse

r petro

sa...

Greater p

etros..

.

Chorda t

ympani

Inferio

r alveo...

0%

16%

4%

62%

18%

1. Greater palatine2. Lesser petrosal3. Greater petrosal4. Chorda tympani5. Inferior alveolar

SUBMANDIBULARGANGLION

CILIARY GANGLION

Oculomotor Nerve (Pre) Ciliary Ganglion Short Ciliary Nerves (Post)

VASCULATURE 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?

Foramen ovale

Foramen ro

tundum

Foramen sp

inosum

Foramen la

cerum

Sphenopalatine fo

ramen

6% 4% 4%4%

82%1. Foramen ovale2. Foramen

rotundum3. Foramen

spinosum4. Foramen

lacerum5. Sphenopalatine

foramen

MIDDLE MENINGEAL ARTERY 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?

Anterior c

ereb...

Middle ce

rebra...

Posterio

r cere...

Posterio

r comm...

Ophthalmic a

rt...

2% 2% 2%

19%

75%1. Anterior cerebral

artery2. Middle cerebral

artery 3. Posterior cerebral

artery4. Posterior

communicating artery

5. Ophthalmic artery

CIRCLE OF WILLIS 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?

Transverse sin

...

Superio

r sagit..

.

Occipita

l sinu...

Straight s

inus

Sigmoid sin

us

75%

0%

10%8%8%

1. Transverse sinus2. Superior sagittal

sinus3. Occipital sinus4. Straight sinus5. Sigmoid sinus

THE CONFLUENCE OF THE SINUSES 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

NECK 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?

Superfi

cial (i

...

Preverte

bral f...

Pretrach

eal fa...

Susp

ensory lig

...

Pyramid lobe o...

8%

18%

2%

30%

42%1. Superficial

(investing) fascia

2. Prevertebral fascia

3. Pretracheal fascia

4. Suspensory ligaments

5. Pyramid lobe of the thyroid

FASCIAL LAYERS OF NECK 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. Between the trachea and the carotid sheath

2. Between the trachea and the strap muscles

3. Between the trachea and the esophagus

4. Between the esophagus and the prevertebral muscles

5. Between the trapezius and the prevertebral muscles

Between th

e tr...

Between th

e tr...

Between th

e tr...

Between th

e es...

Between th

e tr...

20%

6%0%

53%

20%

RETROPHARYNGEAL SPACE 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?

crico

thyroid

thyro

arytenoid

posterio

r cric

...

lateral cr

icoa...

vocal

is

35%

10%

4%

14%

37%1. cricothyroid2. thyroarytenoid3. posterior

cricoarytenoid4. lateral

cricoarytenoid5. vocalis

THE LARYNX 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)

LYMPHATICS 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?

submental

submandibular

Inferio

r jugu

lar

buccal

parotid

98%

2% 0%0%0%

1. submental2. submandibular3. Inferior jugular4. buccal5. parotid

MAJOR DRAINAGE PATTERNS 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

EMBRYOLOGY Branchial Arches Eye Development Ear Development

Know the precursors

25. FROM WHICH OF THE BRANCHIAL ARCHES IS THE AFFECTED NERVE DERIVED?

First

Seco

nd Third

Fourth Fi

fth

21%

66%

0%2%

11%

1. First2. Second3. Third4. Fourth5. Fifth

26. THE EXTERNAL AUDITORY MEATUS DEVELOPS FROM WHICH OF THE FOLLOWING EMBRYOLOGIC STRUCTURES?

First

branchia...

Seco

nd branch

i...

Third branch

ia...

First

branchia...

Seco

nd branch

i...

18%11% 11%

57%

2%

1. First branchial arch

2. Second branchial arch

3. Third branchial arch

4. First branchial cleft

5. Second branchial pouch

BRANCHIAL ARCH DERIVATIVESArc

h Nerve Skeletal Structures Muscles

1 CN VMandible, malleus,

incus, greater wing of sphenoid

Muscles of mastication, mylohyoid, anterior belly of

digastric, tensor tympani, tensor veli palatini

2 CN VIIStylohyoid

process, stapes, upper body & lesser horn of

hyoid

Muscles of facial expression, stylohyoid, stapedius, postberior

belly digastric

3 CN IXLower body &

greater horn of hyoid

Stylopharyngeus

4CN X

Superior larynge

alThyroid cartilage

Cricothyroid, levator veli palatini, palatopharyngeus, palatoglossus,

pharyngeal constrictors

5-6CN X

Recurrent

laryngeal

Cricoid cartilage Intrinsic muscles of larynx (except cricothyroid & stylopharyngeus)

BRANCHIAL CLEFTS & POUCHES

27. THE SEMICIRCULAR CANALS DEVELOP FROM THE _________________ OF THE OTIC VESICLE, WHICH IS ITSELF DERIVED FROM _______________.

Utricu

lar part.

..

Utricu

lar part.

..

Saccu

lar part;

...

Saccu

lar part;

...

15% 17%23%

45%1. Utricular part; surface ectoderm

2. Utricular part; neural ectoderm

3. Saccular part; surface ectoderm

4. Saccular part; neural ectoderm

INNER EAR DEVELOPMENT 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)

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

28. WHERE DO TEARS ENTER THE NASAL CAVITY?

Inferio

r meatus

Middle m

eatus

Superio

r meatus

Sphenopalatine fo

ramen

Pterygomaxillary

fissure

58%

22%

7%11%

2%

1. Inferior meatus2. Middle meatus3. Superior meatus4. Sphenopalatine

foramen5. Pterygomaxillar

y fissure

SINUS DRAINAGE 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?

Superio

r orbit..

.

Inferio

r orbit..

.

Optic can

al

Sphenopalatine...

Pterygoid cana...

22%

45%

16%12%

4%

1. Superior orbital fissure

2. Inferior orbital fissure

3. Optic canal4. Sphenopalatine

foramen5. Pterygoid canal

TO ORBIT

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

PRACTICAL 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?

Earlie

r

A week is

good La

ter

8%

25%

67%1. Earlier2. A week is good3. Later

Good luck!