The Umbilical Cord
The Ultimate Instruction Set
Pregnancy starts when the sperm fertilizes the egg and the combination of the two sets of DNA fuse to become its own unique composition. To borrow language from computer science, a new ‘Instruction Set’ has been created. This set of instructions follow a predictable path of development. At around three weeks a primitive version of the umbilical cord known as the umbilical stalk is formed that connects directly to the placenta. During this time, other temporary structures are created including the vitelline duct which connects to the yolk sac in order to provide the baby with nutrients.
A Baby’s Lifeline
When referring to Cord Blood Banking, the cord in the title refers to the Umbilical Cord which is a complex structure containing two umbilical arteries and one umbilical vein. The two arteries can be seen as the waste system as their main function is to remove waste products such as deoxygenated blood and waste products. In contrast, the umbilical vein brings nutrients and oxygen rich blood to the baby. The umbilical artery is the larger of the three structures. The umbilical cord also contains ‘Wharton’s Jelly’ which is a gelatinous substance made up of mucopolysaccharides, collagen and stem cells. Its function is to cushion and maintain the structural integrity of the umbilical cord. It is also a major source of primitive ‘Mesenchymal Stem Cells.’ For more information on the different types of stem cells, see our post on ‘Stem Cells.’
Umbilicus translates as navel in Latin, which means that the umbilical cord is literally the navel cord. Like a rope, it is a structure that acts as a lifeline connecting the foetus to the placenta. Its job is to carry oxygen and nutrients as well as a conduit for removing waste. Interestingly, parts of the adult abdominal wall contain remnants of this birth cord.
Groundbreaking Research
In 1989, a groundbreaking paper entitled ‘Human umbilical cord blood as a potential source of transplantable hematopoietic stem/progenitor cells’ was published in U.S. National Academy of Sciences (NAS). The paper published by H E Broxmeyer, G W Douglas, G Hangoc, S Cooper, J Bard, D English, M Arny, L Thomas and E A Boyse concluded that “human umbilical cord blood from a single individual is typically a sufficient source of cells for autologous (syngeneic) and for major histocompatibility complex-matched allogeneic hematopoietic reconstitution.”
Broxmeyer, H.E., Douglas, G.W., Hangoc, G., Cooper, S., Bard, J., English, D., Arny, M., Thomas, L. and Boyse, E.A. (1989). Human umbilical cord blood as a potential source of transplantable hematopoietic stem/progenitor cells. Proceedings of the National Academy of Sciences, 86(10), pp.3828–3832. doi:https://doi.org/10.1073/pnas.86.10.3828.
The aim of the study was to discover wether or not human umbilical cord blood could be used as an alternative to bone marrow. Bone marrow was hsitorically the main source of hematopoietic stem cells (HSCs.)
