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Stem Cell Definition
Stem Cell – an undifferentiated, primal cell that has the capability to endlessly divide and develop into numerous types of cells.Totipotent stem cells exist primarily in the early embryo (blastocyst) and can differentiate into (become) virtually any type of cell in the body. As the body becomes more complex and develops beyond the blastocyst stage, stem cells become specialized to produce certain kinds of cells, which they retain the ability to do endlessly.
These stem cells, though found in tissues of all kinds throughout the body, are most highly concentrated in the bone marrow (blood stem cells). umbilical cord blood is another source of highly concentrated blood stem cells. Blood stem cells can differentiate into any type of blood cell.
Researchers have had some success with stimulating blood stem cells, in the laboratory, to function as though they were other types of cells such as nerve cells or muscle cells, and are hopeful that stem cells will someday become a source of cultivated replacement tissues and organs. Multipotent stem cells that occur in other tissues are difficult to identify and extract from their source tissues though may also hold similar potential.
For further discussion of stem cells within the context of the structures and functions of genetics, please see the overview section “Genetics and Molecular Medicine.”
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