Are there different types of stem cells?
Yes. The stem cells described above are pluripotent stem cells. Pluripotent stem cells can become any type of cell in the body. These stem cells only exist during the beginning of an organism’s development, when it is an embryo, and are often called embryonic stem cells. Adult stem cells exist in a developed organism, and are more limited than embryonic stem cells. These stem cells can usually only become a few types of specialized cells, based on the tissue in which they originate. For example, a particular adult stem cell may only be able to differentiate into different types of blood cells, such as a red blood cell, a white blood cell or a platelet. These adult stem cells are also called multipotent stem cells. There is evidence that certain types of adult stem cells can differentiate into a broader range of cell types than was originally thought. For instance, brain stem cells have been shown to differentiate into blood and skeletal muscle cells.
