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Tom Eck – ecktw@umdnj.edu. HAD UNIT II CALM REVIEW. 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 - PowerPoint PPT Presentation
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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
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!
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