Umbilical cord. Coloured Scanning Electron Micro- graph (SEM) of a sectioned human umbilical cord. Here, the umbilical vein (blue, at right) is seen cut through to reveal its wider inner lumen than the artery (blue, at left). These blood vessels consist largely of circular layers of smooth muscle (purple). Around these vessels is a jelly- like mucous connective tissue (pink) known as Wharton's jelly. A second artery is not seen due to the umbilical cord having been cut (far right). The umbilical cord connects the foetus with the placenta, providing nourishment from the mother's blood. Magnification: x11 at 6x7cm size. x16 at 4x5"~LANDSCAPE"