The development, structure and blood flow within the umbilical cord with particular reference to the venous system

Abstract

The umbilical cord is a helical and tubular blood conduit connecting the foetus to the placenta. The umbilical cord achieves its final form by the 12th week of gestation and normally contains two arteries and a single vein, all embedded in Wharton's jelly. The structure of the umbilical cord receives only a cursory glance during many obstetric ultrasound examinations: with imaging limited to documenting the number of vessels within the cord and the insertion sites at the foetus and placenta. Extensive research into blood flow characteristics of the umbilical cord arteries has been undertaken and is now widely applied in contemporary ultrasound practice. In contrast, investigation of umbilical vein blood flow is only instigated in instances of foetal compromise when the spectral waveform of the ductus venosus and pulsations in the vein are scrutinised. The current level of ultrasound imaging of the umbilical vein demonstrates a lack of appreciation and knowledge about a structure that is crucial to sustaining foetal life.The goal of this review is to increase awareness of the importance of the umbilical cord. In addition, this review will provide an information platform for undertaking and critically analysing research into the umbilical cord by providing a summary of cord embryology, structure, foetal venous circulation and mechanisms of blood flow within the umbilical cord vein.

Evaluation of dehydrated human umbilical cord biological properties for wound care and soft tissue healing

“…The histological images of dHUC revealed a spongy tissue. Additionally, the dHUC tissue stained positively for both collagen type I (Figure A) and hyaluronic acid (Figure B), the two most abundant matrix components in umbilical cord tissue . The images demonstrated an even distribution of these extracellular matrix components throughout the tissue (Figure D).…”

“…Histological assessment revealed that the primary native ECM components found in the Wharton's jelly of umbilical cord tissue, collagen I and HA, are retained in dHUC after processing (Figure ). Because dHUC allografts are devitalized, cell nuclei are intact and still present in the tissue, as shown by DAPI staining.…”

“…Although these fetal membranes have been successfully used for the treatment of chronic wounds, the umbilical cord has garnered increasing attention as an allograft for soft tissue healing . The umbilical cord transports oxygen and nutrients from the placenta to the fetus during gestation and is composed of amnion epithelium, two arteries, one vein, and Wharton's jelly . Wharton's jelly is a collagenous matrix within the umbilical cord that protects the umbilical vessels and contains an abundance of hyaluronic acid (HA) .…”

“…The umbilical cord transports oxygen and nutrients from the placenta to the fetus during gestation and is composed of amnion epithelium, two arteries, one vein, and Wharton's jelly . Wharton's jelly is a collagenous matrix within the umbilical cord that protects the umbilical vessels and contains an abundance of hyaluronic acid (HA) . Much research has focused on the cells isolated from umbilical tissue as well as umbilical cord blood; however, the cord itself has not been well characterized.…”

Overview of methods of isolation, cultivation and genetic profiling on human umbilical cord stem cells

“…Human umbilical cord is a structure connecting fetus to the placenta and it develops at 4 th to 8 th weeks of pregnancy, while the blood circulation within the cord is established by the end of the 5 th week. At term, it is 40-60 cm long and 1-2 cm wide [10]. Several main regions of the cord can be distinguished, speifically an outer single layer of amniotic epithelium, the subamnion, the intervascular Wharton's jelly and a perivascular region, that surrounds the umbilical vessels (two arteries and one vein) [9].…”