Anatomi Sistem Saraf Pusat

SISTEM SARAF PUSAT dan TEPI(mencakup komponen fungsional:

motorik, sensibel/sensorik, otonom, luhur)

Komponen otak Fungsi otak

Korteks serebrum Persepsi sensorik

Kontrol gerakan volunter

Bahasa

Sifat pribadi

Proses mental canggih (berpikir, mengingat, membuat keputusan)

Nukleus basal Inhibisi tonus otot

Koordinasi gerakan yang lambat dan menetap

Penekanan pola gerakan yang tidak berguna

Talamus Stasiun pemancar untuk semua masukan sinaps

Kesadaran kasar terhadap sensasi

Beberapa tingkat kesadaran

Berperan dalam kontrol motorik

Komponen otak Fungsi otak

Hipotalamus Mengatur fungsi homeostasis (suhu, haus, urin, asupan makanan)

Penghubung penting antara sistem saraf dengan endokrin

Emosi dan pola perilaku dasar

Serebelum Memelihara keseimbangan

Peningkatan tonus otot

Koordinasi dan perencanaan aktivitas otot volunter yang terlatih

Batang otak Asal dari sebagian besar saraf kranialis perifer

Pusat pengaturan kardiovaskuler, respirasi, dan pencernaan

Pengaturan refleks otot yang terlibat dalam keseimbangan & postur

Penerimaan dan integrasi semua masukan sinaps dari korda spinalis

Pusat tidur

Lobus Otak • Lobus Oksipitalis

– Posterior penglihatan• Lobus Temporalis

– Lateral sensasi suara• Lobus Parietalis

– Di puncak kepala di belakang sulkus sentralis menerima sensasi sentuhan, tekanan, panas, dingin, nyeri, posisi tubuh

• Lobus Frontalis– Di korteks bagian depan mengatur aktivitas motorik

volunter, kemampuan berbicara, dan elaborasi pikiran

Bagian-bagian otak:• A. Berdasarkan letak:

– Prosencephalon, terdiri dari:a. Telencephalonb. Diencephalon

– Mesencephalon– Rombencephalon, terdiri dari:

a. Cerebellumb. Ponsc. Medulla oblongata

• B. Berdasarkan fungsi1. Cerebrum, terbagi menjadi:

a. Hemisfer cerebri dextrab. Hemisfer cerebri sinistraKeduanya dipisahkan oleh fisura longitudinalis

– Struktur cerebrum terdiri dari sulcus dan gyrusLobus pada cerebrum:a. Lobus frontalis → untuk pergerakanb. Lobus parietalis → untuk sensori (rasa/raba)c. Lobus temporalis → untuk pendengarand. Lobus okcipitalis → untuk penglihatan

• 2. Cerebellum, terbagi menjadi:a. Hemisfer cerebri dextrab. Hemisfer cerebri sinistraKeduanya dipisahkan oleh fisura formis

• 3. Truncus cerebri– Medulla spinalis terbagi menjadi:

a. Cervical → 8 Cb. Torakal → 12 Tc. Lumbal → 5 Ld. Sacral → 5 Se. Koksigeal → 3 pasang

Lapisan Pelindung

SSP

Sawar Darah Otak

Korteks Serebrum• Terbagi menjadi hemisfer kanan dan kiri• Terdiri dr substansia alba & grisea• Fungsi :

– Persepsi sensorik– Kontrol gerakan volunter– Bahasa– Sifat pribadi– Berpikir, mengingat,

membuat keputusan, kreativitas, dan kesadaran diri

Daerah Fungsional Korteks Serebrum

Kemampuan Berbahasa

VASKULARISASI OTAK

Arteries to Brain Schema

Vaskularisasi Otak • Arteri karotis interna regio sentral dan lateral hemisfer.• Arteri serebri anterior korteks orbitalis, frontalis, parietalis

bagian tengah, korpus kalosum dan nukleus kaudatus.• Arteri serebri media korteks orbitalis, lobus frontalis,

parietalis dan temporalis. • Arteri vertebralis batang otak dan medula spinalis atas. • Arteri basilaris pons. • Arteri serebri posterior lobus temporalis, oksipitalis, sebagian

kapsula interna, talamus, hipokampus, korpus genikulatum dan mamilaria, pleksus koroid dan batang otak bagian atas.

• Arteri koroidal pleksus koroid temporal lateral ventrikel.

Vaskularisasi otak - arteri

Vaskularisasi otak - vena

Superior sagittal sinus laid open after remova of the skull cap. The chordæ Willisii are clearly seen. The venous lacunæ are also well shown; from two of them probes are passed into the superior sagittal sinus

38

Middle Cerebral Artery

39

Anterior Cerebral Artery

40

Anterior Cerebral Artery

Middle Cerebral Artery

41

Posterior Cerebral Artery

42

Posterior Cerebral Artery

hartono prabowo 43

BasilarArtery

Vertebral Artery

PosteriorCerebralArtery

44

•

•

CCA

ICA

ACA

MCA

PCA

VA

BA

45

MCA

ACA

PCA

46

ACA

PCA

MCA

47

ACA

MCA

PCA

hartono prabowo 48

Cerebral Venous System

Nervus Kranial

Cranial Nerves

• Terdapat 12 pasang nervus kranialis

• Meninggalkan otak melalui foramen-foramen kranial

• Beberapa berupa motorik, sensorik atau berupa campuran

Cranial Nerve I: Olfactory

Berasal dari epitel olfaktorius, melalui celah cribriform oleh os ethmoid, serabut saraf menjalar menuju korteks

Berupa kemoreseptor penciuman

CN I. Olfactory – four respects1. The somas of the primary

afferent neurons occupy a surface of epithelium.

2. The axons of the primary afferents enter the cerebral cortex directly.

3. The primary afferent neurons undergo continuous turnover, being replaced from basal stem cells.

4. The pathway to the highest cortical centers (in the frontal lobe) is entirely ipsilateral.

Olfactory

Unilateral Anosmia

Bilateral Anosmia

ANOSMIA

Head Trauma

Frontal Meningioma

Especially with leakage

of cerebrospinal

fluid

Cranial Nerve II: Optic

Arises from the retina. Optic nerves pass through the optic canals and converge at the optic chiasm. They continue to the thalamus where they synapse and the optic radiation fibers run to the visual cortexCarries afferent impulses for vision (Sensory) Symptoms of dysfunction: loss of vision

Visual Pathway

Retina

N. II

OpticalChiasma

Optical Tract

CGL

Opt. Radiation

Primary Visual Cortex

Lesions of the visual pathwaysLesions Field defects

Partial CN. II. Ipsilateral scotoma.

Complete CN. II.

Blindness in that eye.

Optic chiasm. Bitemporal hemianopia

Optic tract. Homonymous hemianopia.

Meyers loop Homonymous upper quadrant anopia.

Optic radiation Homonymous hemianopia.

Visual cortex Homonymous hemianopia.

Bilateral macular cortex

Bilateral sentral scotomas

CN. III (Oculomotor) , CN. IV (Trochlear) & CN. VI (Abducen)

• Motor nerves that innervate muscles of eye and orbit

• Leave cranial cavity by passing through superior orbital fissure to enter orbit

• Supply total of 9 muscles of the eye that include 6 skeletal muscles arising from the walls of the orbit and attaching to the eye, 2 smooth muscles within eye and 1 skeletal muscle of upper eyelid

Function of CN III, IV, VIRL6 (SO4)3

Cranial Nerve III: Oculomotor

Fibers extend from the ventral midbrain, pass through the superior orbital fissure, and go to the extrinsic eye muscles (4 of 6). Functions in raising the eyelid, directing the eyeball, constricting the iris, and controlling lens shape. (Parasympathetic cell bodies are in the ciliary ganglia)

CN. III: Oculomotor

Major functions: innervates all extraocular muscles - except superior oblique and lateral rectus – and striated muscles of eyelid

Motor: eye movements – elevation (superior rectus when the eye is abducted and inferior oblique when adducted), depression (inferior rectus when eye is abducted), adduction and elevates upper eyelid

Parasympathetic: pupillary constriction in response to light; increases convexity of lens for near vision

Symptoms of dysfunction: double vision, drooping eyelid, deviation of eye outward, uneven dilation of pupils

CN. IV: Trochlear CN. VI: Abducens

• Motor• Innervates superior

oblique muscle• Depresses the

adducted eye• Symptoms of

dysfunction: double vision

• Motor• Innervates lateral

rectus muscle• Major function in

eye movement – abduction of eye

• Symptoms of dysfunction: double vision and inward deviation of eye

Cranial Nerve IV: Trochlear

Fibers emerge from the dorsal midbrain and enter the orbits via the superior orbital fissures; innervate the superior oblique musclePrimarily a motor nerve that directs the eyeball

Cranial Nerve VI: Abducens

Fibers leave the inferior pons and enter the orbit via the superior orbital fissurePrimarily a motor nerve innervating the lateral rectus muscle

Complete left III Nerve paralysis

Complete left VI nerve paralysis

Weber Syndrome

Pyramidal tract - contralateral UMN syndrome at the body and lower face (contralateral hemiparesis)

Oculomotor Nerve - ipsilateral ocular palsy - external strabismus - mydriasis - loss of accommodation - normal consensual light reflex

CN. V: Trigeminal

• Mixed motor and sensory• Has small motor root and large

sensory root; extends from brain stem to sensory ganglion (trigeminal ganglion) found in apex of petrous temporal bone

• Nerve divides into 3 branches beyond ganglion: V1(Opthalmic), V2 (Maxillary) and V3 (Mandibular)

• Sensory fibers enter each of divisions, motor fibers only enter V3 (only one mixed)

CN. V: Trigeminal

• V1 enters orbit through superior orbit fissure

• V2 enters pterygopalatine fossa through foramen rotundum

• V3 exits through foramen ovale to reach infratemporal fossa

• Major functions: -V1 – innervate structures of the orbit,

nose and forehead and scalp back to vertex of skull

-V2 – provide sensation from the skin over the cheek and to upper portion of oral cavity

CN. V: Trigeminal

- V3 – supplies sensation from the skin over the jaw , the area over the ear and the lower part of the oral cavity, including tongue (supplies muscles of mastication)

Symptoms of dysfunction: numbness in face, weakness and wasting of jaw muscles, brief attacks of severe pain, asymmetric chewing

Cranial Nerve V: Trigeminal

Trigeminal Neuralgia(tic douloureux)

- excruciating episodic pain in the area supplied by trigeminal nerve, especially second and third division- trigger point- intense pain makes the patient grimace (tic)- antiepileptic drug (phenytoin, carbamazepine) is effective- surgical treatment

Cranial Nerve VII: Facial

Fibers leave the pons, travel through the internal acoustic meatus, and emerge through the stylomastoid foramen to the lateral aspect of the faceMixed nerve with five major branchesMotor functions include facial expression, and the transmittal of autonomic impulses to lacrimal and salivary glandsSensory function is taste from the anterior two-thirds of the tongue

CN. VII: Facial

• Also parasympathetic and preganglion fibers

• Leaves cranial cavity by passing through internal auditory meatus where sensory ganglion is located; then runs in a bony facial canal in the temporal bone and exits the base of the skull through stylomastoid foramen; divides into terminal branches on face

VII. Facial Nerve

1. Facial Motor Nucleus

2. Superior Salivatory

Nucleus

3. Nucleus Tractus Solitarius

4. Spinal Tract Nucleus of V

VI. Abducens Nerve 5. Abducens Nucleus

Cranial Nerve VII: Facial

CN. VII: Facial

• Major functions: sensory – supply taste buds in anterior two-thirds of

tongue motor – innervates muscles of facial expression

(smiling, frowning, whistling)• Parasympathetic – innervates salivary glands except

parotid, as well as lacrimal glands and cerebral vasculature

• Symptoms of dysfunction: facial paralysis, loss of taste over anterior two-thirds of tongue

Right facial paralysis

Facial Palsy (Bell’s Palsy)

Central TypeFacial Palsy

Upper MotorNeuron

Syndromefacial motor nucleus neuronssupplying forehead muscle

Bilateral Corticobulbar Tract

Facial Palsy(Bell’s Palsy)

Lower MotorNeuron

SyndromeTriple W Sign - Wrinkle, Wink, Whistle

Cranial Nerve VIII: Vestibulocochlear

Fibers arise from the hearing and equilibrium apparatus of the inner ear, pass through the internal acoustic meatus, and enter the brainstem at the pons-medulla border. Two divisions – vestibular (balance) and cochlear (hearing)Functions are solely sensory – equilibrium and hearing

CN. VIII: Vestibulocochlear

• Sensory• Two components: cochlear and vestibular• Leaves cranial cavity by entering internal auditory

meatus; ends in specialized receptors of the inner ear located in the petrous temporal lobe

• Major functions: vestibular nerve conveys information regarding changes in position and movements of head needed to maintain equilibrium; cochlear aids in hearing

• Symptoms of dysfunction: deafness, feeling of distortion in space, dysequilibrium

CN. IX: Glossopharyngeal

• Mixed, with large sensory and small motor components, also parasympathetic and preganglion fibers

• Leaves cranial cavity by passing through jugular foramen in company of nerves X & XI to reach lateral aspect of pharynx

• Major functions: Sensory – supplies mucosa of posterior tongue and pharynx

including tonsillar area, so branches convey sensation and taste; provide sensory supply to specialized receptors in carotid body and sinus for reflex regulation of of blood pressure and respiration

CN. IX: Glossopharyngeal

• Motor – supplied one muscle of pharynx, the stylopharyngus; aids in swallowing

• Parasympathetic – innervates parotid gland; essential for secretion of saliva

• Symptoms of dysfunction: spasms of pain in posterior pharynx, maybe in fall of blood pressure

CN. X: Vagus

• Mixed and has additional large parasympathetic portion

• Leaves cranial cavity by passing through jugular foramen, along with IX & XI to reach lateral aspect of pharynx and larynx

• Major functions: Motor – supplies skeletal muscles of

pharynx, larynx and soft plate (important in swallowing)

Sensory – mediates sensation from posterior pharynx, visceral sensation from pharynx, larynx, thoracic and abdominal organs

CN. X: Vagus

Parasympathetic – innervates smooth muscle and glands of gastrointestinal, pulmonary, cardiovascular systems in neck, thorax and abdomen

• Symptoms of dysfunction: hoarseness, poor swallowing, loss of gag reflex

Cranial Nerve X: Vagus

Fibers emerge from the medulla via the jugular foramen - a mixed nerveMost motor fibers are parasympathetic fibers to the heart, lungs, and visceral organsIts sensory function is in taste

                                                                                                                                    

                     

The Human Cranial Nerves Parasympathetic Ganglia

General Visceral Efferent Nuclei (GVE)

Dorsal Motor Nucleus of Vagus X

Inferior Salivatory Nucleus IX

Superior Salivatory Nucleus VII

Edinger-Westphal Nucleus III

Cranial Nerve XI: AccessoryFormed from a cranial root emerging from the medulla and a spinal root arising from the superior region of the spinal cord. The spinal root passes upward into the cranium via the foramen magnum. The accessory nerve leaves the cranium via the jugular foramenPrimarily a motor nerve -supplies fibers to the larynx, pharynx, soft palate, trapezius, and sternocleidomastoid

CN. XI: Spinal Accessory

• Motor• Arises from upper cervical spinal cord

and enters cranial cavity through foramen magnum; leaves via jugular foramen

• Major function: innervates trapezius and sternocleidomastoid muscles

• Symptoms of dysfunction: inability to shrug, wasting of neck with weakened rotation

CN. XII: Hypoglossal• Motor• Leaves cranial cavity through hypoglossal (anterior condylar)

canal• Major function: innervates muscles of tongue• Symptoms of dysfunction: wasting of tongue with deviation to

side of lesion on protrusion

Wallenberg SyndromeSpinothalamic tract - contralateral loss of pain and temperature sensation at the body

Spinal tract of trigeminal nerve - ipsilateral loss of pain and temperature sensation at the face

Nucleus ambiguus - dysphageia, dysarthria, hoarseness

Descending autonomic pathway - Horner’s syndrome (miosis, ptosis, anhydrosis)

•Sensory:

•I  Olfactory •II  Optic •VIII  Vestibulocochlear

                                                    

                                                             

•Mixed Sensory & Motor:

•V   Trigeminal •VII  Facial •IX   Glossopharyngeal •X  Vagus

•Motor:

•III  Oculomotor •IV  Trochlear •VI  Abducens •XI Accessory •XII Hypoglossal

•Parasympathetic:

•III  Oculomotor •VII  Facial •IX   Glossopharyngeal •X Vagus

•Key:    Blue - sensory    Green - motor    Red - mixed

Summary of cranial nerve

Summary of Function of Cranial Nerves

Nerve & Component fibres

S = Sensory M = MotorP = Parasympathetic

Function Structures innervated

I Olfactory S smell olfactory bulbsII Optic S vision retinaIII Oculomoto

r Meyeball movement

4 eyeball muscles & 1 eyelid muscle

lens accomodation

 

III Oculomotor P pupil

constriction 

IV Trochlear M eyeball movement

superior oblique muscles

V Trigeminal S sensations face, scalp, teeth, lips, eyeballs, nose & throat lining

general sensory from tongue

anterior two thirds of tongue

proprioception muscles of masticationV Trigeminal M chewing muscles of mastication

Summary of cranial nerve

Summary of cranial nerve

VI Abducens M eyeball movement

lateral rectus muscle

VII Facial S taste anterior two thirds of tongue

proprioception

face & scalp

VII Facial M facial expressions

muscles of the face

VII Facial P salivation and lacrimation

salivary and lacrimal glands via submandibular and pterygopalatine gamglia

VIII Vestibulocochlear

S balance vestibular apparatus of internal ear

hearing cochlear of internal ear

Nerve & Component fibres

S = Sensory M = MotorP = Parasympathetic

Function Structures innervated

Summary of cranial nerve

X Vagus S chemoreceptors blood oxygen concentration, aortic bodies

pain receptors respiratory & digestive tractssensations external ear, larynx &

pharynxtaste tongue

X Vagus M heart rate & stroke volume

pacemaker & ventricular muscles

peristalsis smooth muscles of digestive tract

air flow smooth muscles in bronchial tubes

speech & swallowing

muscles of larynx & pharynx

XI  Spinal Accessory

M head rotation trapezius & sternocleidomastoid muscles

XII Hypoglossal

M speech & swallowing

tongue & throat muscles

Nerve & Component fibres

S = Sensory M = MotorP = Parasympathetic

Function Structures innervated

CRANIAL NERVES

GSA SpSA VA GSE SpVE GVEV VIII

a. N. Cochl.

b. N. Vest.

Sp.VA I, V, VII,

IX, X

III, IV, VI, XII

V, VII, IX, X, XI

III, VII, IX, X

GVAIX, X

No. Disease / Symptoms

Lesion of Oculomotor Nerve

III~Droopy eyelid; pupil dilation - unresponsive to light & accommodation; inability to move eyeball up, down and inwards.

Lesion of Abducens Nerve

VI ~Inability to move eyeball outwards.

Lesion of Trigeminal Nerve

V

~Herpes zoster infection of sensory roots of Trigeminal Nerve leads to pain & eruption of vesicles of dermatome supplied by opthalmic, maxillary & mandibular branches of trigeminal nerve.~Syringobulbia leads to selective loss of pain & temperature sensibility in the face.

Lesion of Facial Nerve VII

~Bell's palsy - pain around ear; paralysis of the facial muscles; failure to close eye; absent corneal reflex; hyperacusis on affected side; loss of sensation in anterior two thirds of tongue

Lesion of Vestibulocochlear Nerve

VIII~Acoustic neuroma - dizziness & deafness; ataxia & paralysis of the cranial nerves (especially V - VII) and limbs

The Human Cranial Nerves Diseases of the Cranial Nerves

Cranial nerve

Nucleus name Nucleus location Function Symptom/sign of damage

Olfactory (CNI)

Anterior olfactory

Olfactory tract

Smell Anosmia

Optic (CNII)

Lateral geniculate nucleus

Thalamus Vision Blindness, hemianopsia

Oculomotor (CNIII)

OculomotorEdinger Westphal

MidbrainMidbrain

Eye movement(elevation, adduction)

Eye deviates down & outLoss of pupillary/accommodation reflexes

Trochlear (CNIV)

Trochlear Midbrain Eye movement(depression of adducted eye)

Diplopia, lateral deviation of eye

Trigeminal (CNV)

PrincipalSpinalMesencephalicMotor

PonsMedullaPons/midbrainPons

Facial sensationMastication

Facial aneasthesia Loss of pain sensationInsignificantWeakness/loss of mastication

CRANIAL NERVES: SUMMARY TABLE.

CRANIAL NERVES: SUMMARY TABLE.

Abducent (CNVI)

Abducent Pons Eye movement (Abduction)

Medial eye deviation

Facial (CNVII)

MotorSolitarySuperior salivatory

PonsPonsPons

Facial expresssion TasteSalivation, lacrimation

Paralysis of facial nerve muscles (+ hyperacuisis)Loss of taste (anterior 2/3rds of tongue)Dry mouth, loss of lacrimation

Vestibulocochlear (CN VIII)

VestibularCochlear

MedullaMedulla

BalanceHearing

Vertigo, dysequilibrium, nystagmusHearing

Glossopharyngeal (CN IX)

Nucleus ambiguusInferior salivatorySolitary

MedullaMedullaMedulla

TasteSalivationInnervation of pharynx

Loss of taste (posterior 1/3rd of tongue)InsignificantLoss of gag reflex

Cranial nerve Nucleus name Nucleus location

Function Symptom/sign of damage

Vagus (X) Nucleus ambiguusDorsal motor vagal Solitary

MedullaMedullaMedulla

Swallowing & talkingCardiac, GI tract, respirationTaste

Dysphagia & hoarseness of voiceInsignificantLoss of cough reflex (larynx/pharynx), loss of taste (hard palate)

Cranial Accessory (XI)Spinal accessory

Nucleus ambiguusSpinal accessory

MedullaCervical cord

Pharynx/larynx musclesNeck & shoulder movement

InsignificantHead turning/shoulder shrugging weakness

Hypoglossal (XII)

Hypoglossal

Medulla Tongue movement

Atrophy of tongue muscles, deviation on protrusion, fasciculaations

CRANIAL NERVES: SUMMARY TABLE.

Cranial nerve

Nucleus name

Nucleus location

Function Symptom/sign of damage