What are Stem Cells?
Stem cells are considered the primordial cells of living organisms and are often referred to as the "building blocks of life." Their primary functions include building, repairing, and regenerating tissues. An adult human has approximately 100 trillion individual body cells, which can be divided into 200 different types of cells. All of these cells originated from a single stem cell – the fertilized egg. The fact that, in about 40 weeks of pregnancy, a whole human being – a new living organism – develops from this is a wonder of nature.
After the fertilization of the egg, cell division begins at an astonishing rate. Within three to four days, the zygote develops into the blastocyst – and from there, the embryo forms. During this brief period, stem cells are "multi-talented" and can develop into any specific cell type. However, as the embryonic cells continue to divide, this ability diminishes. Cell development becomes a sort of one-way street, where each cell type is assigned a specific function. Embryonic stem cells first become fetal and later adult stem cells. These cells continue to play an important role in the human body until death, as they can renew diseased organs and tissues to a certain extent and repair damage.
