What Are Stem Cells?

          What are stem cells? According to the Longevity Meme (2007), stem cells are cells with no set function, which means that they have ability to differentiate and become any part within body, for example cartilage, muscle or bone cells and many more. The future for stem cells is bright and they have the potential to become a great medical breakthrough. There are two different types of stem cells, adult, and embryonic, and they each have different properties with different pros and cons. (Wikipedia, 2008; The Longevity Meme, 2007)

          According to Wikipedia (2008), stem cells have many possible uses within medical therapies, including regenerative medicine, which means that stem cells have the potential to prolong life (The Longevity Meme, 2007). Stem cells can also speed up the natural healing process. Stem cells and regenerative medicine can be used to treat damaged nerves, broken bones, broken tissues, damaged hearts and many other medical conditions (The Longevity Meme, 2007). Aging causes internal damage, but while this is very minor and can not be harmful by itself, it still adds up. Regenerative medicine used with stem cells can heal some of this internal damage.

          According to the National Institute of Health (2008) research on stem cells is providing more knowledge about how an organism develops from one cell. This research also studies how healthy cells can replace damaged cells in humans and animals. Because stem cells are unspecialized cells, which mean that they have not taken a particular form yet, with special physiologic conditions, they can become cells with specialized functions, such as heart tissue.

          The history of stem cells started 20 years ago, according to the National Institute of Health (2008), when some of the first stem cells were taken from mouse embryos. Wikipedia (2008) states that all stem cells have two properties, which are potency and self-renewal. Potency means being able to turn into various types of cells, and self-renewal is being able to go through unlimited cell divisions without changing.

          In a 3-5 day old embryo, called a blastocyst, stem cells in developing tissue differentiate into the many specialized cell types that form the human body, making up the heart, lungs, skin, and all other tissue. These are embryonic stem cells. In grown tissue, such as bone marrow, muscle, and brain, tiny groups of adult stem cells generate replacements for cells that are lost normally; these are adult stem cells (National Institute of Health, 2008). Some scientists predict that in the future, stem cells could treat diseases such as Parkinson's disease, diabetes, and heart disease.

All stem cells have the same unique properties. According to the National Institute of Health (2008) all stem cells have three general characteristics. First is that they can divide and renew themselves, second is that they are unspecialized, and the third property is that they can change into specialized cell types.

Also, stem cells cannot work with their neighbor and pump blood, they cannot carry oxygen through the blood stream, or give signals to other parts of the body, like nerve cells, but they can do all of these things if they transform and are specialized to do them. The National Institute of Health (2008) also states that stem cells may replicate many times, and this is called proliferation. If stem cells proliferate for a few months in a lab, the result could be millions of unspecialized stem cells. When stem cells change into a specialized cell this is called differentiation, and then this cell is no longer unspecialized. (National Institute of Health, 2008)