Doctors did not create your belly button (or navel). The navel is not the scar or knot left by a doctor that cut your umbilical cord at birth. This fact is obvious to anyone that has ever had children or bathed newborns, but it is sometimes misunderstood by others. While you were in your mother's womb, your umbilical cord attached to your navel at one end and to your placenta at the other end. The placenta is a pancake-shaped mass of blood vessels that attaches to the wall of the mother's uterus. Food that your mother ate and oxygen that she breathed went into her blood, and then was carried to her uterus. Where your placenta and your mother's uterus touched, the food and oxygen was exchanged from your mother's blood to your blood. Your blood than carried the nutrients from the placenta, down the umbilical cord, through your navel,