Final answer:
The fetal portion of the placenta is developed from the trophoblast, namely the cytotrophoblast cells, while the maternal part develops from the deepest layer of the endometrium, known as the decidua basalis. These components interact to form the placenta, essential for nutrient and gas exchange between the mother and fetus.
Step-by-step explanation:
The fetal portion of the placenta develops from the trophoblast, specifically from a layer of cells called the cytotrophoblast which contributes to the formation of the chorionic villi. These villi are tree-root like structures that penetrate the maternal endometrium and are essential in blood supply to the developing fetus. The maternal part of the placenta develops from the decidua basalis, which is the deepest layer of the endometrium. It interacts with the chorionic villi to form the site of nutrient and gas exchange between the mother and fetus.
Throughout pregnancy, the placenta advances its growth to fulfill the needs of the growing fetus. It does this by facilitating an intricate exchange of blood and nutrients through proximate but separate maternal and fetal blood vessels. This relationship allows vital substances to pass to the fetus without the two blood supplies mixing. The placenta is connected to the conceptus via the umbilical cord, which includes two umbilical arteries and one umbilical vein, surrounded by Wharton's jelly within the amnion.