Umbilical cord diameter. This diameter decreases rapidly within the placenta. The fully patent umbilical artery has two main layers: an outer layer consisting of circularly arranged smooth muscle cells and an inner layer which shows rather irregularly and loosely arranged cells embedded in abundant ground substance staining metachromatic. The smooth muscle cells of the layer are rather poorly differentiated, contain only a few tiny myofilaments and are thereby unlikely to contribute actively to the process of post-natal closure. The umbilical cord contains Wharton's jelly, a gelatinous substance made largely from mucopolysaccharides which protects the blood vessels inside. It contains one vein, which
Murder of pregnant women among women ages 20 to 24 and fifth among women ages 25–34 in 1999. The top cause of death in both age groups is accidents. The Unborn Victims of Violence Act, passed in 2004, defines a fetus as a "child in uterus" and a person as being a legal crime victim "if a fetal injury or death occurs during the commission of a federal violent crime." In the U.S., 38 states have laws with more harsh penalties if the victim is murdered while pregnant. Some of these laws defining the fetus as being a person, "for the purpose of criminal