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
Lateral umbilical fold due to the placement of the opening of the deep inguinal ring in the space lateral to the lateral umbilical fold, which allows the passage of the ductus deferens, testicular artery, and other components of the spermatic cord in men, or the round ligament of the uterus in women. Lateral umbilical fold The lateral umbilical fold overlies the inferior epigastric artery (a branch of the external iliac artery) and its accompanying veins. Unlike the median and medial umbilical folds, the contents of the lateral umbilical fold remain functional after birth. It originates just medial to the deep inguinal ring to