18.4 The fetus in the uterus
The placenta is an organ that provides oxygen and nutrients to the fetus and removes waste products from it. The placenta attaches to the wall of the uterus, and the baby's umbilical cord arises from it.
The fetus in the uterus.
The fetus receives oxygen, nutrients, hormones and antibodies from the mother's bloodstream. Water and harmful substances such as urine and carbon dioxide are released from the fetus into the mother's blood. The placenta filters out most harmful substances, but is permeable to alcohol, tobacco toxins, viruses, bacteria, certain drugs and narcotics. This is why consuming such products during pregnancy is harmful to the fetus.
