The placenta is a temporary organ that develops in the uterus during pregnancy to provide nourishment and support to the developing fetus. It is formed from both maternal and fetal tissues and is attached to the uterine wall via the umbilical cord. The placenta facilitates nutrient, oxygen, and waste exchange between the mother and fetus while preventing mixing of their blood supplies. It produces hormones important for maintaining the pregnancy and regulating physiological processes. After birth, the placenta is expelled from the uterus during the third stage of labor.