IMED2004 Study Guide - Final Guide: Cloacal Membrane, Epiblast, Gastrulation
Document Summary
Epiblast cell in prim streak undergo mitosis: Prolif, develop pseudopodia, and migrate through prim groove and replace hypoblast with new layer. 2nd wave of migration: epiblast cells in region of prim streak proliferate and migrate through prim groove and create 3rd layer of cells in between endoderm and existing epiblast. Non migrating epiblast cells differentiate and become ectoderm. Cells that migrate through primitive pit form notochord. No mesoderm at oropharyngeal membrane nor cloacal membrane. As mesoderm migrates, does it laterally and cranially. Looking at dorsal view of embryo so that can see migration of mesoderm. Epiblast that migrates through prim pit to form mesoderm in midline. It occupies space between epiblast and endoderm entirely except in 2 places: No infiltrating mesoderm can pass that space. = opening of tube where ectoderm and endoderm together. > give rise to skin, and lining of gut tube.
