Development of the Central Nervous System Biomedic Dept Development of the Central Nervous System Biomedic Dept. Medical School, Unisba

Origin of Nervous System CNS-The brain and spinal cord ectoderm neural epithelium. Proliferation  neural plate  neural groove  neural fold  neural tube.

Proliferation  neural plate  neural groove  neural fold  neural tube. Neural Tube  CNS (Brain&spinal cord) Neural Crest  PNS & ANS(Cranial, spinal, autonomic ganglia) The rest is neural crest .

Neuralation Formation of the neural plate and neural tube(22-23 days)region of the fourth to sixth pairs of somite Two third craniallyfuture brain One third caudally spinal cord Fusion of the neural folds  neural canalrostral neuropore (cranial)&caudal neuropore(

1. Ektoderm 2. Neural tube bagian dorsal 3. Neural tube 4 1. Ektoderm 2. Neural tube bagian dorsal 3. Neural tube 4. Neural tube bagian ventral 5. Notochord

Gen-gen yang berperan dalam perkembangan neural tube A Sensory Neuron B Viscero sensory neuron/motoric C Motoric neuron Gen PAX3/7 berperan dalam perkembangan Alar plate Gen PAX 6 berperan dalam perkembangan basal plate Defisit dari gen ini menyebabkan Syndrome de Waardenburg

Development of The Spinal Cord

Development of The Spinal Cord 3 concentric zones: Ependymal/ ventricularlayer (internal) nucleated , mitotic cells Mantle/intermediate layer (middle) the cell bodies of neuron and neuroglial cells marginal layer (outer) fibrous mass, processes of nerve cells.

Development of the Spinal Ganglia Neural crest cellsSpinal ganglia Peripheral process(dendrit)pass the spinal n. to sensory endings Central processdorsal roots of spinal nerve Myelination of nerve fiber oligodendrocyte

Development of spinal meningens Positional changes of the spinal cord: The vertebral column and duramater grow more rapidly than the spinal cordpositional spinal cord does not persist New born(terminate L2/L3)& Adult (inferior L1)

Congenital anomalies of spinal cord

Development of The Brain

1 Telencephalon 2 Diencephalon 3 Mesencephalon 4 Cerebellum 5 pons 4+5 Metencephalon 6 Myelencephalon(medulla oblongata) 7 Spinal cord I Prosencephalon II Mesencephalon III Rhombencephalon A Cerebral trunk  

Development of brain Fusion of the neural folds in the cranial region & closure of the rostral neuropore form 3 primary brain vesicles Primitive brain  straight  three point of expansion:Forebrain,Midbrain&Hindbrain fore brain (prosencephalon) mid brain (mesencephalon) hind brain (rhombencephalon).

Fourth week :embryonic brain grows rapidly and bends ventrally with the head fold Flexure : cephalic/mid brain, cervical, pontine

MYELENCEPHALON -Most caudal part called medulla oblongata neuroblast(alar plate) marginal zone  gracili nuclei medially& cuneate nuclei laterally -Continued into spinal cord. -Vascular mesenchymechoiroid plexure .

Neuroblast(basal plate)medial tp lateral: general somatic efferent(hypoglosal nerve), special visceral efferent(innv. Muscle from pharyngeal arches), general visceral afferent(vagus & glossopharyngeal nerve) Neuroblast(alar plate)1. general visceral afferent(impulses from the viscera) 2. special visceral afferent(taste fibers)3.general somatic aff. (Impulses from the surface of the head) 4. special somatic aff(impulses from the ear)

METENCEPHALON -From isthmus to pontine flexure. -Dorsal: cerebellum -Ventral: pons MESENCEPHALON -Least modified -Overshadowed by fore and hind brains

DIENCEPHALON. -Epithalamus,thalamus,hypothalamus. -Evagination  epiphysis -The wall optic chiasm -Infundibulum  hypophysis. TELENCEPHALON -Paired cerebral hemisphere -Three functions  corpus striatum, rhinencephalon and pallium.

Congenital anomalies of brain Anencephaly (Meroencephaly) Microcephaly Hydrocephalus

Cranium Development of cranium Cranium develops from mesenchyme around the developing brain. The cranium consists of:Neurocranium Viscerocranium

Congenital anomalies of cranium Cranium bifidum Acrania Holo-acrania

Vertebrae Development of vertebral Mesenchymal cells are found in three main areas: around the notocord, surrounding the neural tube, and in the body wall Cartilaginous Stage Bony stage Notocord expands to form the gelatinous center of the intervertebral disc -- the nucleus pulposus

Congenital anomalies of vertebrae Rachischisis Spina Bifida

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