Cranial Ppt

8/6/2019 Cranial Ppt

1/29

1. Cranial nerves are parts of the PNS.

2. They are attached to the part of the CNS called the

brain stem (midbrain, pons and medulla).

3. Exceptions are I and II which connect directly to

higher levels of the brain.

4. Innervate:

Skeletal muscles

Sensory structures

Smooth muscles, cardiac muscles and

secretory glands (ANS)

CRANIAL NERVES: PRINCIPLESCRANIAL NERVES: PRINCIPLES

OF ORGANIZATIONOF ORGANIZATION


2/29

BRAIBRAI

NN

SS

PP

II

NN

AA

LL

CC

OO

RR

DD

SPINALSPINALNERVES,NERVES,Plexuses &Plexuses &

GangliaGanglia

CRANIALCRANIAL

NERVES,NERVES,Plexuses &Plexuses &

GangliaGanglia

PERIPHERALPERIPHERALNERVOUSNERVOUS

SYSTEMSYSTEM (PNS)(PNS)

CENTRAL NERVOUSCENTRAL NERVOUSSYSTEM (CNS)SYSTEM (CNS)

Head &Head &

neckneckincludingincluding

visceraviscera

Head, neck,Head, neck,thorax,thorax,

abdomen,abdomen,

pelvis,pelvis,

includingincluding

viscera,viscera,

and limbsand limbs

SkeletalSkeletalmuscle,muscle,

SensorySensorystructures,structures,

SmoothSmoothmusclemuscle**,,

CardiacCardiacmusclemuscle**,,

SecretorySecretoryglandsglands**

TARGETTARGET

STRUCTURESSTRUCTURES

*Innervated by the ANS*Innervated by the ANS

OVERVIEW OF THE NERVOUS SYSTEMOVERVIEW OF THE NERVOUS SYSTEM

REGIONSREGIONS


3/29

CRANIAL NERVES:CRANIAL NERVES:

GENERAL FEATURESGENERAL FEATURES

TWELVE PAIRS

ATTACHED TO

BRAIN STEM

Brain stem:

Midbrain,

Pons, and

Medulla


4/29

II

IIII

IIIIII

IVIV

V1V1

VIVI

VIIVIIVIIIVIII

IXIX

XXXIXI XIIXII

V2V2V3V3


5/29


6/29


COMPOSITIONCOMPOSITION

Some are motor nerves III, IV, VI, XI, XII

Some are sensory nerves I, II, VIII

Others are mixed nerves V, VII, IX, X

Some contain autonomic(preganglionic III, VII, IX, X

parasympathetic) fibers

originating in the brain stem


7/29


NUCLEINUCLEI

MotorNucleusMotor

Nucleus SkeletalMuscle

SkeletalMuscle

ParasympatheticNucleus

ParasympatheticNucleus

ParasympatheticGanglion

ParasympatheticGanglion

SmoothMuscleCardiacMuscleGlands

SmoothMuscleCardiacMuscleGlands

SensoryGanglionSensoryGanglion

SkinMucosaSkinMucosa

Sensory

Nucleus

Sensory

Nucleus

MIDBRAINMIDBRAIN

PONS

MEDULLAOBLONGATAMEDULLAOBLONGATA

BRAIN STEM


8/29

AUTONOMIC NERVOUS SYSTEM

Innervates structures that arenot under voluntary control

Target structures are: smooth

muscles, cardiac musclesand secretory glands


9/29

AUTONOMIC NERVOUS SYSTE

Sympathetic Nervous System (SNS)

= ThoracolumbarThoracolumbaroutflow

cell bodies of origin in T1-L2 cord segments

Parasympathetic nervous System (PSNS)

= CraniosacralCraniosacraloutflow

cell bodies of origin in brain stem and S2-S4 cord

segments

Both SNS andPSNS have CNS andPNS

components


10/29

< < TARGETS

Two Neurons in series involved

in ANS innervations

Pre-ganglionic Ganglion Post-ganglionic

CNS:T1-L2 cord,Brain

stem, S 2-4 cord

PNS:

Headandneck,

thorax,abdomen,

pelvis


11/29

V: TRIGEMINALV: TRIGEMINAL

Mixed nerve with both sensory and motormotor

functions

Has a motor root and a sensory root

Because it has a sensory component, it

has a sensory ganglion, akin to the spinal

ganglion

Does NOT contain preganglionicparasympathetic fibers as it leaves the brainstem

SS MM


12/29

TRIGEMINALTRIGEMINALTRIGEMINALTRIGEMINAL

V1 (OPHTHALMIC): SENSORY

V2 (MAXILLARY): SENSORY

V3 (MANDIBULAR): SENSORY and MOTORMOTOR

Three branches:

SS MM


13/29

EXIT THROUGH FORAMINA AT THE BASE OF THE SKULL


GENERAL FEATURESGENERAL FEATURES

IIII

IIIIII

IVIVV1V1VIVI

VIIVII

VIIIVIIIIXIXXX

II

V2V2

V3V3

XIIXII

XIXI

XIXI


14/29

TRIGEMINAL:

COURSE AND FEATURES

TRIGEMINAL:

COURSE AND FEATURES

V1 : Superior orbital fissure OrbitSupraorbital notch

and foramen

V2

: Foramen rotundum Pterygopalatine fossa

Inferior orbital fissure

Infraorbital foramen

V3: Foramen ovale Infratemporal fossa

Mandibular canalMental foramen

Terminal branches in the face become cutaneous nerves in the head

including the face.


15/29

Preganglionic fibers for these ganglia come from other cranial

nerves and only the postganglionic fibers are conveyed by v to

the target structures. Trigeminal has no preganglionic

parasympathetic components arising from the brain stem.

Preganglionic fibers for these ganglia come from other cranial

nerves and only the postganglionic fibers are conveyed by v to

the target structures. Trigeminal has no preganglionic

parasympathetic components arising from the brain stem.

V TRIGEMINAL:V TRIGEMINAL:

GIVES ATTACHMENT TO 4 PARASYMPATHETIC GANGLIA:GIVES ATTACHMENT TO 4 PARASYMPATHETIC GANGLIA:

CILIARY GANGLION, ATTACHED TO V1

PTERYGOPALATINE GANGLION, ATTACHED TO V2

SUBMANDIBULAR GANGLION, ATTACHED TO V3

OTIC GANGLION ATTACHED TO V3


16/29

MAJOR FUNCTIONS: MOTOR: V3 MUSCLES OF MASTICATION*MAJOR FUNCTIONS: MOTOR: V3 MUSCLES OF MASTICATION*

Not shown:

Medial & lateral

Pterygoids

Moves jaw

during

chewing/

Mastication;under

voluntary and

reflex

conditions

Moves jaw

during

chewing/

Mastication;under

voluntary and

reflex

conditions

* 4 others: Mylohyoid, ant. belly of Digastric, Tensor tympani, Tensor palati


17/29

SENSORYDISTRIBUTIONOF V V1

V2

V3


18/29


Conveys sensations (touch, pain, pressure etc.)

from skin of the head (face and scalp) and

mucosa of cavities in the head

Responsible for consciously perceived pain

emanating from the head: toothache, headache

and sinus pain

SENSORY FUNCTIONS

Provides sensory input for for 2 reflexes oftentested during a neurologic examination:

Corneal reflex & Jaw jerk


19/29

Does not contain preganglionicparasympathetic axons.

Gives attachment to 3 parasympathetic

ganglia.

Helps distribute postganglionicparasympathetic fibers to lacrimal and two

salivary glands.

V TRIGEMINAL

Parasympathetic Functions


20/29


HAVE THE PATIENT RECOGNIZE TOUCH AND PAIN

FROM THE SKIN TERRITORIES SUPPLIED BY EACH

DIVISION.

COMPARE THE TWO SIDES FOR EQUAL/UNEQUAL

RESPONSES

NEUROOGICAL EXAM-SENSORY


21/29

Cranial Nerve Video # 5


22/29


THE PATIENT LOOKS TO ONE SIDE

THE OPPOSITE CORNEA IS GENTLYSTIMULATED BY A WISP OF COTTON.

THE NORMAL RESPONSE IS A

BILATERAL CLOSURE OF THE EYES.

V1 IS THE AFFERENT LIMB OF THEREFLEX AND THE EFFERENT LIMB IS VII.

CORNEAL REFLEXCORNEAL REFLEX

NEUROOGICAL EXAM-SENSORY


23/29

Cranial Nerve Video #6


24/29


Have the patient clench her teeth and

Palpate the contraction of the masseter

And temporalis muscles.

Have the patient move mandible, look for normal

movements without any deviation to either side

NEUROOGICAL EXAM-MOTOR


25/29


JAW JERKJAW JERK

Keep the jaw relaxed and the mouth slightly open

Tap the chin to stretch the temporalis and masseter

Jaw closure in response

Normally weak or absent, exaggerated in some

motor neuron diseases

NEUROOGICAL EXAM-MOTOR


26/29

Cranial Nerve Video # 7


27/29

V TRIGEMINAL:

DYSFUNCTIONSV TRIGEMINAL:

DYSFUNCTIONS

1. Loss of sensations in areas innervated.

2. Loss of corneal reflex when affected eye

is stimulated. Stimulation of the intact eye will result ina bilateral normal response.

3. Paralysis of muscles of mastication,

resulting in difficulty in chewing, and aflattening of the side of the face


28/29

RelatedArticles, Links

Neurol Clin.2004 Feb;22(1):185-206.

Trigeminal neuralgia andglossopharyngealneuralgia.

Rozen TD.

Michigan Head-Painand Neurological Institute, 3120Professional Drive,AnnArbor,

MI 48104, [email protected]

Trigeminal neuralgia andglossopharyngealneuralgiaare

extremelypainful conditionsthattypicallyafflictanolder

population. Distinct clinical characteristicsguidethediagnosis

oftheseuniquesyndromes. Treatmentinvolvesmedication

firstandthensurgicalproceduresifapatientisrefractoryto

medicinaltherapy.Antiepileptic medicationsarethemost

effectiveagents forthesedisorders.


29/29


THE MORE COMMONLY MANIFESTED CONDITIONS ARE:

TRIGEMINAL NEURALGIA TRIGEMINAL NEURALGIA

HERPES ZOSTERAFFECTING TRIGEMINAL

GANGLION

HERPES ZOSTERAFFECTING TRIGEMINAL

GANGLION

DYSFUNCTIONS

Cranial Ppt

Documents

Transcript of Cranial Ppt