9.29 Gastrulation Flashcards
the inner cell mass splits, differentiating into the ______ (above) and ______ (below). Which of these will develop into the embryo?
epiblast
hypoblast
epiblast will develop into embryo
the epiblast divides again by formation of a space called the ______ cavity. The top layer is the ___________ and the bottom is the _____.
amniotic
amniotic membrane
epiblast
the position where the epiblast cells migrate towards the midline and move inwards (ingress) to form more layers is called the:
primitive streak
migratory cells (in general) from the epiblast are called:
mesenchyme
the first cells to involute during gastrulation make the ________.
endoderm
the cells that fill the space between the endoderm and the epiblast become the _______, and the ones that remain in the epiblast become the _____.
mesoderm
ectoderm
the thickening of the primitive streak at the cephalic end is called the __________
primitive node
_______ cells migrate directly cranially from the primitive node.
notochord cells
the _______ is a rigid structure that serves as a simple embryonic spine and is critical for signaling.
notochord
The ____ and _____ membranes are the two places that the mesenchyme does not fill
oral
cloacal
what do the oral and cloacal membranes form, respectively?
the mouth and the anus
if the primitive streak does not regress completely, it could give rise to _____________.
sacral teratomas
what derivatives come from the ectoderm germ layer?
outer layer of skin (epidermis), neural tissues
what derivatives come from the endoderm germ layer?
gut tube, bladder, liver, pancreas, lungs
what derivatives come from the mesoderm germ layer?
skeletal and smooth muscle, heart and blood vessels, blood, bones, dermis of skin.
