During pregnancy changes in the

placenta The placenta is a temporary embryonic and later fetal organ (anatomy), organ that begins embryonic development, developing from the blastocyst shortly after implantation (embryology), implantation. It plays critical roles in facilitating nutrien ...

involve the disappearance of the greater portion of the

stratum compactum The decidua is the modified mucosal lining of the uterus (that is, modified endometrium) that forms every month, in preparation for pregnancy. It is shed off each month when there is no fertilised egg to support. The decidua is under the influen ...

, but the deeper part of this layer persists and is condensed to form what is known as the basal plate. Between this plate and the uterine muscular fibres are the

stratum spongiosum The decidua is the modified mucosal lining of the uterus (that is, modified endometrium) that forms every month, in preparation for pregnancy. It is shed off each month when there is no fertilised egg to support. The decidua is under the influe ...

and the boundary layer; through these and the basal plate the uterine arteries and veins pass to and from the intervillous space. Decidual septum is one of the structures derived from basal plate.

References

External links

Slide at uottawa.ca
Embryology {{Portal bar, Anatomy