Redirected from: Afterbirth

This is the free portion of the full article. The full article is available to licensed users only.
How do I get access?

Placenta

Synonyms

Definition

The placenta is a semi-permeable membrane that serves as a support organ for the fetus by facilitating the exchange of oxygen, nutrients, and waste products between the fetus and the mother.

Description

The placenta is a composed of a semi-permeable membrane that is dark reddish-blue or maroon in color. It averages nine inches (22 cm) in length and seven inches (18 cm) in diameter. The placenta typically weighs about one pound (500 g).

Relevance to Childhood Development

The placenta develops out of tissue from both the outer layer of the blastocyst (trophoblast) and the lining of the mother's uterus. It is connected to the fetus via the umbilical cord. The purpose of the placenta is twofold. First, as a semi-permeable membrane, the placenta serves as an exchange site between the fetus and the mother by permitting the passage of some materials between them. Oxygen and nutrients are transmitted from the mother to the fetus, while carbon