The The development of development of nervous systemnervous system

陳建榮陳建榮

http://web.nchu.edu.tw/pweb/users/chenjr/

Nervous system:-Central nervous system (CNS):

-brain, -spinal cord

-Peripheral nervous system (PNS): -cranial nerves, -spinal nerves

-Autonomic nervous system (ANS)

Origin of nervous system

Neutralization:-Notochord -Neural plate-Neural groove -Neural tube, neural crest -Rostral neuropore, caudal neuropore

Nonfusion of neural tube

Neual tube:-Neural canal central canal-Neuroepithelial cell (pseudostratified columnar epi)

-Ventricular zone-Intermediate zone-Marginal zone

-Alar plate dorsal horn-Basal plate ventral horn-Roof plate-Floor plate

-Mesenchyme spinal meninges-Dura matter-Arachnoid -Pia matter

Development of spinal cord

Development of Pseudounipolar neuron

Myelination of nerve fibers

Positional changes of spinal cord

8 weeks 24 weeks child adult

Neural crest

Congenital anomalies of spinal cord Neural tube defects (NTD)

Spinal bifida oculta 隱性脊柱雙裂 Spinal bifida cystica 脊柱雙裂囊腫

Spinal bifida cystica 脊柱雙裂囊腫Myeloschisis 脊髓裂

Neural tube defects (NTD)

Myeloschisis 脊髓裂

Development of brain3 primary vesicles:-Forebrain (prosencephalon)

-Telencephalon - cerebral hemispheres-Diencephalon - thamaus

-Midbrain (mesencephalon)-Mesencephalon - midbrain-Metencephalon - pons, cerebellum-Myelencephalon - medulla

-Hindbrain (rhombencephalon)

Brain flexures 腦彎-Midbrain flexure-Cervical flexure-Pontine flexure

Myelencephalon （ medulla ）

Caudal portion

Rostral portion

Alar plate-Special somatic afferent (SSA)

-CN VIII (hear, vestibular)-General somatic afferent (GSA)

-CN V-Special visceral afferent (SVA)

-CN VII, IX, X (taste)-General visceral afferent (GVA)

-CN XBasal plate:-General visceral efferent (GVE)

-CN IX, X-Special visceral efferent (SVE)

-CN V, VII, IX, X-General somatic efferent (GSE)

-CN III, IV, VI, XII

Metencephalon

Midbrain

Diencephalon

Pituitary gland:-Adenohypophysis (oral ectoderm)

-Hypophysial pouch-Pars tuberalis-Pars distalis-Pars intermedia

-Neurohypophysis (neural ectoderm)-Neurohypophysial bud

-Pars nervosa-Infundibular stem-Median eminence

Pituitary gland

Ventricles of CNS

Telencephalon

13 weeks

21 weeks

32 weeks

25 weeks38 weeks

Early stage of nervous system-Proliferation-Migration -Differentiation-Organization

Corpus callosum 胼胝體

Choroid plexus

Cerebrospinal fluid (CSF)

Hydrocephalus 水腦

- excessive formation of CSF

- blockage of the circulation of CSF

- diminished absorption of CSF

Cranium bifidum 顱骨雙裂

Microcephaly

Agenesis of corpus callosum

Holophrosencephaly

Hydrocephalus

Hydrocephalus

Arnold-chiari malformation

Cranial nerves:-Somatic efferent cranial nerves

-Hypoglossal nerve (CN XII)-Abducent nerve (CN VI)-Trochlear nerve (CN IV)-Oculomotor nerve (CN III)

-Nerves of pharyngeal arches-Trigeminal nerve (CN V)-Facial nerve (CN VII)-Glossopharyngeal nerve (CN IX)-Vagus nerve (CN X)-Accessory nerve (CN XI)

-Special sensory nerves-Olfactory nerve (CN I)-Optic nerve (CN II)-Vestibulocochlear nerve (CN VIII)

Nerves of pharyngeal arch