Figure 5.

Placental organisation in mid gestation. (A) Immunostaining for α-actin. Only the labyrinth (lab) possesses fetal vessels (red staining of the endothelium), in contrast to the trophospongium (tsp). (B) TEM. The labyrinth includes a second centre of proliferation, represented by trophoblast cells (ct) near the fetal capillaries (fc), whereas syncytial trophoblast faces towards the maternal blood channels (mbc). Scale bars = 0.1 mm for histology and 2 μm for TEM.