anat2341 lecture 7 - beverdam - mesoderm development · no screen snap shots or copying of quiz...
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Mesoderm Development
DrAnnemiekBeverdam– SchoolofMedicalSciences,UNSWWallaceWurth BuildingRoom234– [email protected]
Resources:http://php.med.unsw.edu.au/embryology/
Larsen’s Human EmbryologyThe Developing Human: Clinically Oriented Embryology
Week 3 Lecture overview
DrAnnemiekBeverdam– SchoolofMedicalSciences,UNSWWallaceWurth BuildingRoom234– [email protected]
Gastrulation
Early Mesoderm Development
Notochord
Paraxial Mesoderm
Intermediate Mesoderm
Lateral Plate Mesoderm
GastrulationWeek 3
Ingression of epiblast cells: EMT transitionGeneration of definitive endoderm
Generation of intra-embryonic mesodermOropharyngeal and cloacal membrane
Embryonic ectoderm
http://php.med.unsw.edu.au/embryology/images/5/55/Mesoderm_001.mp4
End product gastrulation:Trilaminar embryo
Ectoderm (Neural crest)brain, spinal cord, eyes, peripheral nervous system
epidermis of skin and associated structures, melanocytes, cranial connective tissues (dermis)
Mesodermmusculo-skeletal system
limbsconnective tissue of skin and organsurogenital system, heart, blood cells
Endodermepithelial linings of gastrointestinal and respiratory tracts
Page342S.F.GilbertDevelopmentalBiology5thedition
Embryonic development:
EarlyMesodermDevelopment
EarlyMesodermDevelopment
1 23 4
NeuralTube
1:notochord2:paraxialmesoderm3:intermediatemesoderm4:lateralplatemesoderm
EarlyMesodermDevelopment
1 23 4
NeuralTube
1:notochord2:paraxialmesoderm3:intermediatemesoderm4:lateralplatemesoderm
1:Notochord
AxialmesodermTransient
DevelopmentNeurenteric canal
Crucialsignalling centreMechanicalroleinembryonicfolding
Notochordal plate
Hollow
Solid
1:Notochord
EarlyMesodermDevelopment
1 23 4
NeuralTube
1:notochord2:paraxialmesoderm3:intermediatemesoderm4:lateralplatemesoderm
2:ParaxialMesoderm
Cranial:Unsegmentedparaxialmesoderm:headmesenchyme
Trunk:Segmentedparaxialmesoderm:somites
2:ParaxialMesodermSomitogenesis
Block-likebilateralcondensationsoftheparaxialmesodermFormevery90minuts inacranialtocaudaldirection(day20today30)
‘Segmentationclock’dependsonHes7 transcription/translation44maxareformed,33remain
Giverisetoaxialskeletonandmusculature,dermisofthetrunk
2:ParaxialMesodermSomiteDevelopment
Somites developinto:- Sclerotome:mesenchymalcells(vertebralbodyandintervertebraldisk)- Dermomyotome:columnarepithelium
Dermomyotome developsinto:- Dermatome:dermisofthetrunk- Myotome:trunkmusculature
2:ParaxialMesodermSomiteDevelopment
Sonichedgehog(Shh)(notochordandfloorplate):ventralsomites.BMP-4:lateralsomites.Wnt familyproteins(roofplate):dorsalsomites.
2:ParaxialMesodermSomiteDerivativeSpecificationdependsonAPlevel/Hox code
7:cervicalregion
12:thoracicregion
5:lumbarregion
5:sacralregion
4:caudalregion(tail)
2:ParaxialMesodermSomiteDevelopment
2:ParaxialMesodermMyotomeDevelopment
Epaxial myotome:epimere:erectorspinaeHypoaxial myotome:hypomere:3primarymusclelayers
MyoD initiatesmyogenesis
2:ParaxialMesodermMyotomeDevelopment
2:ParaxialMesodermDermatomeDevelopment
EmbryonicdermatomeswillformthedermisPostnataldermatomeisastripofskininnervatedbyasinglespinalnerve
EarlyMesodermDevelopment
1 23 4
NeuralTube
1:notochord2:paraxialmesoderm3:intermediatemesoderm4:lateralplatemesoderm
3:IntermediateMesodermSegmentedandunsegmentedintermediatemesoderm
MesonephricductUrogenitalsinus
MesonephrictubulesUretericbuds
3:IntermediateMesoderm3nephricsystems:- Pronephros:regress- Mesonephros:reproductivesystem,andcollectingductandtubulesofthekidney- Metanephros:nephronsofthekidney
EarlyMesodermDevelopment
1 23 4
NeuralTube
1:notochord2:paraxialmesoderm3:intermediatemesoderm4:lateralplatemesoderm
4:LateralPlateMesoderm
Lateralplatemesodermdevelopsinto:- Splanchnic/visceralmesoderm- Somatic/parietalmesoderm
Intraembryoniccoelom:3cavities:- Pericard- Pleural- Peritoneal
Somatic/parietalmesoderm:somatopleure- Closesttoectoderm- Givesriseto:
• Connectivetissueandliningofthebodywall• Bones,ligamentsanddermisofthelimbs
Splanchnic/visceralmesoderm:splanchnopleure- Closesttoendoderm- Givesriseto:
• Cardiacmesoderm(prechordal splanchnicmesoderm)• Bloodvessels• Smoothmusclesofthegut
4:LateralPlateMesoderm
Page342S.F.GilbertDevelopmentalBiology5thedition
Embryonic development:
Week 3 Lecture overview
DrAnnemiekBeverdam– SchoolofMedicalSciences,UNSWWallaceWurth BuildingRoom234– [email protected]
Placentation
Body axes
Gastrulation
Axis formation
Embryo folding
Lecture contents relevant to Labs 3 and 7
Resources:http://php.med.unsw.edu.au/embryology/
Larsen’s Human EmbryologyThe Developing Human: Clinically Oriented Embryology
