Glossary of Medical Terms
A mass of tissue attached to the uterine wall that exchanges nutrients between the mother's circulation and that of the developing fetus. It is sometimes referred to as the "afterbirth." The maternal blood circulation carries oxygen and vital nutrients to the placenta where they are exchanged for waste materials from the fetus. The nutrients are then carried from the placenta to the baby through the umbilical cord, which is attached to the near-center of the placenta. The mother's and baby's blood circulation do not mix, but pass within the placenta around very thin membranes that allow this exchange.