Gastrulation Flashcards
The process by which one group of cells or tissues causes another set of cells or tissues to change their fate?
Induction
What produces the signal?
Inducer
What responds to the signal?
Responder
What is gastrulation?
Process by which the epiblast forms all 3 germ layers (ectoderm, mesoder, endoderm).
What is the primitive streak?
Part of epiblast which orchestrates dorsal-ventral and cephalic-caudal axes
What happens during invagination?
Epiblast cells migrate through primitive streak and repopulation the hypoblast to form the definitive endoderm.
What is the mesoderm?
Cells between the ectoderm and endoderm
Mesenchylmal cells are what?
Embryonic connective tissue that originates from the mesoderm.
What happens in Epithelial Mesenchymal Transition (EMT)?
Epithelial cells lose their organization and migrate as mesenchymal cells where they help to form the mesoderm and neural tube.
From what end does the prechordal plate originate?
cephalic (cranial)
The prechordal plate allows for part of the embryo to develop?
Oropharyngeal membrane
Future site of oral cavity
Prenotochordal cells come from where?
Hypoblast
The notochordal cells detach from where to form the notochord?
Endoderm
Remnants of notochord become what part of the vertebra?
Nucleus pulposus
Where does the amniotic cavity connect with yolk sac?
The primitive pit and the neurenteric canal
The allantois forms from where?
Yolk stalk
No function in mammals
What type of cysts from faulty partitioning of notochordal plate can compress spinal cord?
Neurenteric cysts
What body axes does the primitive streak develop? (3)
Cranial-caudal (probably during morula stage)
Dorso-Ventral
Laterality
Situs inversus totalis
Condition where organs are positioned in a mirror image
Sirenomelia
Congenital disorder where the legs are fused together
Holoprosencephaly
Forebrain fails to divide into two hemispheres
Angio-meaning
relating to blood vessels
Vasculogenesis
Blood vessels form from blood islands
Angiogenesis
Blood vessels sprouting from blood vessels
FGF2
Induces mesoderm cells to form hemangioblasts
VEGF
Induces these cells to form blood cells in the center of the island and peripheral vessels.
Through what process does the embryo receive nutrients prior to week 4?
Diffusion
Later, capillaries develop and the connecting stock becomes the umbilical cord.
Capillary system is established when heart begins to beat
