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
Percutaneous umbilical cord blood sampling issues, and infections. In 1958, James L.S. recognised that umbilical cord blood gas analysis can give an indication of preceding fetal hypoxic stress. It has since become widely accepted that umbilical cord blood gas analysis can provide important information about the past, present and possibly the future condition of the infant. PUBS dates back to 1964 when Freda and Adamsons reported the removal of a uterus containing a fetus who had a buildup of fluid and ended up dying; however, this was one of the first procedures that showed promise for current day PUBS. Valenti hypothesized in 1972 that the