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
The Pregnant Widow The Pregnant Widow The Pregnant Widow is a novel by the English writer Martin Amis, published by Jonathan Cape on 4 February 2010. Its theme is the feminist revolution, which Amis sees as incomplete and bewildering for women, echoing the view of the 19th-century Russian writer, Alexander Herzen, that revolution is "a long night of chaos and desolation". The "pregnant widow", a phrase taken from Herzen's "From the other shore" (1848–1850), is the point at which the old order has given way, the new one not yet born. Amis said in 2007 that "consciousness is not revolutionised by the snap