Histological Classification of Placenta || Hemo-chorial placenta

Hemo-chorial placenta

In lower insectivorous, bats and anthropoids there is developed still more intimate contact between maternal and foetal tissues. 

Here the endothelium of uterine vessels is also lost along with the erosion of uterine lining. Thus the maternal blood freely circulates in the vessels present within the foetal syncytium. In anthropoids, the chorionic villi are very much branched and they penetrate the space between maternal and foetal tissues. 

In the cavernous spaces, the villi are directly bathed by maternal blood. This type of relationship is called hemo-chorial where the chorionic and uterine tissues are fused in such a way that at birth both are torn away as an unit.