||Implantation site 2x3mm. The maternal tissue is invaded by
trophoblast (primary) giant cells and the ectoplacental cone is invaded
by maternal blood. Differentiation of the egg cylinder into embryonic
and extraembryonic regions and the formation of the proamniotic cavity.
Reichert's membrane, which is non-cellular and secreted by the distal
endoderm first appears.
6 dpc (range 5-6.5)
Witschi Stage 10-11 (rat)
Carnegie Stage 5 (human)
Scale bar in microns.