Cranial neuroporeNeuralfoldNeuralfoldCutedgeofamnionPericardial,bulgeNeuralplateOticplacodeNeuralgroovesomiteSomitePrimitivepitCutedgeofamnionPrimitivestreak8ADcaudal neuroporeday 19day 20-21day 22day 23
day 19 day 20-21 day 22 day 23 somite Cranial neuropore caudal neuropore
notochordEctodermNeural plate...-Neuralgroove-..---Neural crest--.Fusion----Neural tubedifferentiationDSEM images:Formation of neural tube1)PrimordiaofCNS2)Retina&Opticnerve
Ectoderm- Neural plate -Neural groove- -Neural crest- -Neural tube notochord Fusion SEM images: Formation of neural tube 1) Primordia of CNS 2) Retina & Optic nerve differentiation
AnteriorneuroporePosteriorneuroporefailtoclosefailtocloseanencephalymyeloschisis (spina bifida)
Anterior neuropore anencephaly fail to close Posterior neuropore myeloschisis fail to close (spina bifida)
2NeuralCrestFormation&DifferentiationNeuralcrestABNotochordNeural grooveSurfaceIntermediatezoneSpinalectodermofneuralcrestganglion00NeuraltubecD1)PrimordiaofPNS,2)Chromaffincellsofadrenal medulla&melanocytes¶follicularcellsofthyroid
1) Primordia of PNS, 2) Chromaffin cells of adrenal medulla & melanocytes & parafollicular cells of thyroid. .2 Neural Crest Formation & Differentiation
.3DifferentiationofSurfaceEctodermEpidermis and its appendages;Adenohypophysis;Sensory epithelium of the ear, nose, tongue;Lens of the eyes;DorsarootaanglioEnamel oftheteeth;SympatheticgangloDevelopingPreaorticglandganglionUrogenitOrganridaeplexus
.3 Differentiation of Surface Ectoderm • Epidermis and its appendages; • Adenohypophysis; • Sensory epithelium of the ear, nose, tongue; • Lens of the eyes; • Enamel of the teeth;