What Are Stem Cells?

Stem cells are undifferentiated cells that have the potential to differentiate into specific cells. These remarkable building blocks of lifeStem Cells can replace or repair damaged tissues and cells. Based on this, scientists insert stem cells into areas of the body to heal or replace tissue and cells effected by disease.

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Three Classifications of Stem Cells:

  1. Totipotent- these are stem cells present in the zygote immediately after fertilization of the egg by the sperm during the first few cell divisions. They can differentiate to not only all cells of the body, but cells of the extraembryonic tissues, such as the placenta.
  2. Pluripotent- these are stem cells that can differentiate into any cell of the body.
  3. Multipotent- these are stem cells whose potential is limited to differentiation into various cells of their tissue of origin.

Researchers see pluripotent stem cells as the holy grail of medicine because of their ability to differentiate into any cell that is needed. The pluripotent are often referred to as "unlimited" stem cells. Turipotent is avoided because extraembryonic tissue is not coveted. Multipotent, while it certainly has great ability and use, is referred to as "limited" stem cells because of their inability to widely differentiate.


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