Question

Designed to exchange materials, what spongy structure consists of membranes and blood vessels from both mother and embryo?

Answer 1

placenta

The placenta is a spongy structure. It consists of membranes and blood vessels from both mother and embryo  see Figure below  . The placenta passes oxygen, nutrients, and other useful substances from the mother to the fetus. It also passes carbon dioxide and other wastes from the fetus to the mother. The placenta lets blood from the fetus and mother exchange substances without actually mixing. Thus, it protects the fetus from being attacked by the mothers immune system as a foreign parasite. .