Definition
The umbilical cord is the connection between the maternal placenta and the embryo or fetus. It represents a bridge between the two bloodstreams and therefore serves both to supply the foetus with oxygen and nutrients and to remove metabolic waste products such as carbon dioxide. In humans, the umbilical cord, which is about 50 cm long, is usually clamped twice at birth and then cut between the clamps.
Anatomy
The umbilical cord in humans is on average about 50 cm long, has a diameter of about 1.5 to 2 cm and is spirally wound. It is formed by the fusion of the yolk duct and the adhesive stem. The yolk duct is the connection between the embryonic intestine and the yolk sac.
The yolk sac is a fluid-filled bulge which loses size during pregnancy and finally disappears almost completely. The adherent stem is the original connection between the embryo and the endometrium and contains the vascular system for the later umbilical vessels. At this point of the endometrium, the placenta then develops, which is responsible for supplying the foetus until birth.
The umbilical cord usually emerges centrally from the placenta, but can also be connected to it laterally. The umbilical cord consists of a “gelatinous connective tissue“, which is also called “Wharton’s jelly” or “Wharton’s jelly”. It contains many collagens and water-binding substances.
This makes the tissue elastic and resembles the consistency of rubber. The resulting stability and flexibility is important to ensure that the fetus can move freely and withstand its “strains”. The tissue is surrounded by the inner egg membrane of the fetus, which is also called “amniotic membrane” and is responsible for the production of amniotic fluid.
The umbilical cord is subject to a constant process of development. In addition to its length and size, its content changes. In the mature umbilical cord, embedded in the connective tissue, are the blood vessels that connect the mother’s circulation with that of the foetus. Due to its rubber-like substance, the connective tissue prevents the umbilical cord and thus the vessels it contains from kinking, thus protecting them. At the time of birth there are usually three vessels in the umbilical cord, the so-called umbilical vein (Vena umbilicalis) and the two umbilical arteries (Arteriae umbilicalis)
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