EMBRYOLOGY OF NERVOUS SYSTEM new13.ppt

8/10/2019 EMBRYOLOGY OF NERVOUS SYSTEM new13.ppt

1/40

Dr.Ardhiyanti PR

Medical School ofAl Azhar Islamic University

Mataram 2013


2/40

2


3/40

1) Describe the formation and differentiation ofthe neural tube.

2) Mention the derivatives of the neural crest.

3) Mention the development of the brain vesicles4) Discuss the derivatives of both basal (motor)

and alar (sensory) laminas in the brain stem.5) Define the development of the brain6)

Recognize the development of the cerebellum.7) Describe the formation and development ofnervous cells.

8) Report its congenital anomalies.

3


4/40

Sistem saraf pusat munculpada permulaan mingguke 3

Sistem saraf tsbberkembang dari

ectoderm dorsalmenjadinotochord

sebagailempeng ectoderm yangmenebalneural plate,

lempeng neural di depanprimitive node.

Batas lateral dari lempeng

neural naiik dan

membentukneural folds,ketika bagian tengahnyaneural groove.

4


5/40

Anterior Neuropore:menutup pada hari ke25 dan membentuklamina terminalis.

kegagalan daripenutupan anteriorneruropore akanmengakibatkananencephaly.

Posterior Neuropore:menutup pada

hari 27.

kegagalan darimenutupnya posteriorneuroporesmengakibatkan

terjadinya spina bifida.

5


6/40


7/40

Beberapa sel

yang ada diatas neuralfold berubahmenjadi neural

crest.

7


8/40

Jaringan yang berasal dari neural crest:

Sell saraf dari basal gangliaSell saraf dari saraf ganglia sensorik pd

nervus cranialisSell saraf dari ganglia Autonomicsell Chromaffin.Sell SchwannPia matter dan arachnoid matter.Sell pigmen di kulit (melanocytes).Odontoblasts.Tulang rangka dan komponen jaringannnya

8


9/40

Perkembangan Vesicle:

1.

Vesicle primer

3 vasicle utama otak otakdepan otak tengah otakblakang dan 2 flexures:

a. Cephalic flexure

terletak di antaraProsencephalonandthe rhombencephalon.

b. Cervical flexureterletakdi antararhombencephalondanmedulla spinalis yangakan terbentuk padaminggu ke 4

9


10/40

2- Vesicles: skunder :

A. Prosencephalon (forebrain):terbentuk sejalan denganmunculnya vasicle optik

Setelah itu terbentuklahtelencephalondan diencephalon.

B.

Mesencephalon (midbrain)Mesencephalon tetep seperti itu

C.

Rhombencephalon (hindbrain):lalu terbentuk metencephalon,yangterdiri dari

pons dan the cerebellum

dan

myelencephalon

yangmembentuk

medulla oblongata.

10


11/40

. 5 vesicel otakskunder (dengan4 ventrikel)

mulai terlihatterlihat padaminggu ke 6perkembangan

dari vesicles otakadalahpermulaan dariterbentuknya 5bagian utama

otak

11


12/40

12


13/40

13


14/40

14


15/40

Diverticulum lateralis di sebutdgn vesicle optic muncul pdmasing_masing bagian dari otak

depan . Bagian dari otak depan

yang terletak di belakang vesicleoptic adlah telencephalon, dandiencephalon.

Telencephalonmenggembangkan diverticulum

lateral pada masing_masinghemisphere cerebral,danrongganya di sebut dgnventricle. lateral

15


16/40

diencephalon,yang di mna yg berkembangdari bagian tengah prosencephalon, terdiridari lempeng atap dan 2 lempeng alar

Rongga dari diencephalon membentuk

ventricle ke 3. Atapnya membentuk plexus choroid Dinding dari ventrikel ke 3 yang merupakan

lempeng aral menebal dan membentukthalamus hypothalamus

16


17/40

Rhombencephalon

terdiri dari pons,cerebellum &medullaoblongata.

rhombencephalonterdiri darimyelencephalon,yang

terletak paling bawah

dari vesicles otak,membentuk medullaoblongata,&metencephalon,dan

juga membentukpons cerebellum.

17


18/40

18


19/40

- medulla oblongata berkembang dari caudalrhombencephalon.terdiri dari tractuspiramidalisSulcus limitans memisahkan Alar (sensory)lateral dari lempeng basalis

Lempeng Alar (sensory) neuroblasts:

membentuk :a. nucleus,Solitary , yang membentuk kolumna

visceral afferent (taste-SVA).b. Trigeminal nucleus ,Spinal yang membentuk

kolumna somatic afferent (GSA) column.c. nuclei vestibular dan Cochlear mereka

membentuk columna somatic afferent yang

khusus(SSA).

19


20/40

20


21/40

2. Neuroblasts lempeng basal (motorik)

membentuk:a. Nucleus hipoglosal,yang membentuk collumna

somatik efferent .b. Ambigus Nucleus ,yang membentuk collumna

visceral efferent khusus (SVE)column (CN IX, CN X,and CN XI).

c. Nervus vagus dan nervus glossopharyngeal yangmembentuk collumna visceral efferent

(parasimpatik)

Lempeng atap:- Membentuk atap dari ventrikel ke 4- tela choroidea, sebuah lapisan sel ependimal yang

dibun gkus oleh pia mater.- invaginated dijepit oleh badan pial untuk

membentuk plexus choroideus ventrikel ke 4

21


22/40

metencephalonterdiri dari pons andcerebellum.

Cerebellum:

bagian dorsolateralisdari lempeng alarmenekuk ke tengah

dan membentukbibir rhombic

22


23/40

1. Lneuroblas lempeng

Alar (sensorik)

membentuk :

:a. Nucleus soliter,

membentuk cranialis 7b.

Cochlear and

vestibularnuclei,which form the SSAcolumn of CN VIII.

c. Spinal nucleus oftrigeminal nerve

,whichforms the GSA columnof CN V.

d.Pontine nuclei:

which consist ofcerebellar relay nuclei(pontine gray).

23


24/40

- The midbrain developsfrom the walls of themesencephalic vesicle.

- It contains the cerebral

aqueduct,whichdevelops from themesencephalic cavity.

A. Alar plate neuroblastsform the cell layers of

the superior colliculiand the nuclei of theinferior colliculi.

24


25/40

25


26/40

B. Basal plate neuroblasts:

give rise to the following:

1. Trochlear and oculomotor nucleiof CN IVand CN III, which form the GSEcolumn.2. Edinger-Westphal nucleusof CN III, which

forms the most rostral cell group of the GVE

column.3. Substantial nigra.4. Basis pedunculi(crus cerebri)- contains corticobulbar, corticospinal and

corticopontine fibers, derived from thecerebral cortex of the telencephalon

26


27/40

Neural tube first lined by single layer of cells

Proliferate to form several layers

Matrix layer Mantle layer

Marginal layer

27


28/40

Stages in the formation of a nerve cell are: Apolar neuroblast

Bipolar neuroblast

Unipolar neuroblast

Multipolar neuroblast Axon and dendrites

28


29/40

Neuroglial cells are also formed fromgerminal cells of the ependymal layer

Glioblasts migrate in to mantle and marginallayer as medulloblasts

They differentiate either into astroblasts oroligodendroblasts

Microglial cells are mesodermal in origin

29


30/40

30


31/40

Nerve fibers which remain with in the brainand spinal cord receives support from and areensheathed by neuroglial cells

Peripheral nerves special sheath called the

neurolemma derived from schwann cells

Myelin of the CNS derived fromoligodendrocytes

31


32/40

32


33/40

results from failure of thecephalic part of the neural tube

to close(failure of the anteriorneuropore to close), the laminaterminalis fails to develop.

occurs when: The brain fails to develop, A rudimentary brain stemis

usually present The vault of the skull does not

form. Occurs once in every 1000-

1500 births. is the most common serious birth

defect seen in stillborn fetuses.

33


34/40

In cases of neural tube defects as in

anencephaly: Serum alpha-fetoprotein (AFP)levels increasein amniotic fluidand maternalserum.

up to 70% of these cases can be prevented by

having women take 400 g of folic acidperday before and during pregnancy.

34


35/40

35


36/40


37/40

Hydrocephalus is typically

characterized by:

1) Thecranial sutures are

widely separated,

and theanterior fontanelle is muchenlarged.

2) Enlargement of the head.3) The veins of the scalpare

distended .4)

The eyeslook downward.

37


38/40

include the following variations:cranial meningocele, meningoencephalocele

and meningohydroencephalocele.

38


39/40

Microcephaly

- The cranial vault issmaller than normal.

- It is due to defect inbrain developmentwhich may be due to

genetic disease,postnatal infections orexposures to drugs andother teratogens.

- Impaired mentaldevelopment occurs inmore than half thecases.

39


40/40

Thank You

Documents

EMBRYOLOGY OF NERVOUS SYSTEM new13.ppt