Stem cells are unspecialized cells that have the ability to differentiate into a variety of specialized cell types. This makes them a valuable tool for research and regenerative medicine. There are two main sources of stem cells: embryonic stem cells and adult stem cells.
The Origins of Stem Cells
Stem cells are derived from the inner cell mass of a blastocyst, which is a hollow ball of cells that forms during early embryonic development. The inner cell mass gives rise to the embryo proper, while the outer layer of cells forms the placenta.
Sources of Stem Cells
Embryonic stem cells are derived from the inner cell mass of a blastocyst. These cells are pluripotent, meaning that they can differentiate into any type of cell in the body. However, embryonic stem cells are controversial because they require the destruction of an embryo.
Adult stem cells are found in small numbers in various tissues throughout the body. These cells are multipotent, meaning that they can differentiate into a limited number of cell types. However, adult stem cells are more difficult to isolate and grow in culture than embryonic stem cells.
Stem cells are a promising tool for research and regenerative medicine. However, the ethical concerns surrounding embryonic stem cells have led to the development of alternative sources of stem cells, such as adult stem cells.
