Difference between revisions of "Gastrulation - Anatomy & Physiology"

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(New page: <big><center>'''BACK TO DEVELOPMENTAL BIOLOGY</center></big>)
 
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<big><center>[[Developmental Biology - Anatomy & Physiology|'''BACK TO DEVELOPMENTAL BIOLOGY]]</center></big>
 
<big><center>[[Developmental Biology - Anatomy & Physiology|'''BACK TO DEVELOPMENTAL BIOLOGY]]</center></big>
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==Introduction==
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Gastrulation is the process of forming the three germ layers; ectoderm; mesoderm; and endoderm. It is achieved through a series of highly coordinated series of cell movements. Cells that will form the endodermal and mesodermal organs are brought inside the embryo, whilst cells that will form ectoderm move to spread out over the outside of the embryo.
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*Ectoderm - outside layer
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*Mesoderm - middle layer
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*Endoderm - inner layer
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{| style="width:70%; height:200px" border="1"
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!'''Germ Layer'''
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!'''Derivatives'''
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|-
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| '''Ectoderm'''
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|'''Neural Ectoderm''' - PNS & CNS
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'''Non Neural Ectoderm''' - Epidermis of skin
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|-
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| '''Mesoderm'''
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|'''Axial Mesoderm''' - Notochord, which is mostly degenerated
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'''Paraxial Mesoderm''' - Somites, which form axial skeleton and dermal muscle of the body
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'''Intermediate Mesoderm''' - Parts of reproductive system and kidneys
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'''Lateral Plate Mesoderm''' - Heart, limbs, tissue around gut
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|-
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| '''Ectoderm'''
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|Parynx, lungs, liver, lining of gut
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|}
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==Mechanism of Gastrulation==
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When the embryo is in it's blastula stage it has two cell layers; the epiblast and hypoblast. The epiblast is columnar whilst the hypoblast is cubiodal - each is a single cell thick. '''The epiblast gives rise to all three cell layers; the hypoblast makes no contribution'''. The endoderm and mesoderm develop by proliferation and migration of cells of the epiblast. What remains of the epiblast forms the ectoderm.

Revision as of 12:53, 25 August 2008

BACK TO DEVELOPMENTAL BIOLOGY

Introduction

Gastrulation is the process of forming the three germ layers; ectoderm; mesoderm; and endoderm. It is achieved through a series of highly coordinated series of cell movements. Cells that will form the endodermal and mesodermal organs are brought inside the embryo, whilst cells that will form ectoderm move to spread out over the outside of the embryo.

  • Ectoderm - outside layer
  • Mesoderm - middle layer
  • Endoderm - inner layer
Germ Layer Derivatives


Ectoderm Neural Ectoderm - PNS & CNS

Non Neural Ectoderm - Epidermis of skin

Mesoderm Axial Mesoderm - Notochord, which is mostly degenerated

Paraxial Mesoderm - Somites, which form axial skeleton and dermal muscle of the body Intermediate Mesoderm - Parts of reproductive system and kidneys Lateral Plate Mesoderm - Heart, limbs, tissue around gut

Ectoderm Parynx, lungs, liver, lining of gut


Mechanism of Gastrulation

When the embryo is in it's blastula stage it has two cell layers; the epiblast and hypoblast. The epiblast is columnar whilst the hypoblast is cubiodal - each is a single cell thick. The epiblast gives rise to all three cell layers; the hypoblast makes no contribution. The endoderm and mesoderm develop by proliferation and migration of cells of the epiblast. What remains of the epiblast forms the ectoderm.