Surface view of implantation site. The mouths of the glands are prominent. The circular fissures about the embryo are readily seen, as are the irregular endometrial pits. The mottled appearance of the embryo is due to underlying maternal blood in trophoblast lacunae as well as to irregularity or degeneration of the overlying endometrium.
Fig. 6. Hertig and Rock, 1941.
Keywords: embryo, endometrial pits, endometrium, implantation site, trophoblast lacunae
Source: The Virtual Human Embryo.