Umbilical cord from and contains remnants of the yolk sac and allantois. It forms by the fifth week of development, replacing the yolk sac as the source of nutrients for the embryo. The cord is not directly connected to the mother's circulatory system, but instead joins the placenta, which transfers materials to and from the maternal blood without allowing direct mixing. The length of the umbilical cord is approximately equal to the crown-rump length of the fetus throughout pregnancy. The umbilical cord in a full term neonate is usually about 50 centimeters (20 in) long and about 2 centimeters (0.75 in) in
Women in the Bible saw her, he thought she was a prostitute, for she had covered her face. Not realizing that she was his daughter-in-law, he went over to her by the roadside and said, 'Come now, let me sleep with you'."(Genesis 38:14) He said he would give her something in return and she asked for a pledge, accepting his staff and his seal with its cord as earnest of later payment. So Judah slept with her and she became pregnant. Then she went home and put on her widow's weeds again. Months later when it was discovered she was pregnant, she was accused