Sunday, April 27, 2008

Body II


Human embryonic stem cells are pluripotent stem cells. They can give rise to all the cell types in the human body, but because they do not give rise to the amnion and chorion they do not have the potential to develop into an organism.
Embryonic stem cells are a primitive type of cell that fixed into developing into most or all 220 types of cells found in the body. Research on stem cells is advancing on how an organism develops from a single cell and how healthy cells replace damaged ones in adult organisms. Stem cells have two important characteristics that distinguish them from other types of cells. They are unspecialized cells that renew themselves for a long period of time through cell division. They can be induced to become cells with special functions such as the beating cells of the heart muscle or the insulin-producing cells of the pancreas (Brennings). Embryonic stem cells are taken from embryos that develop from egg that have been fertilized in a clinic and then donated for research purposes with the consent of the donor. Human embryonic and adult stem cells are not alike in many ways. Human embryonic cells can become every type of cell of the body because they are pluripotent capable of infecting more than one organ or tissue, and adult stem cells are limited to different types of. Embryonic cells can be grown relatively easily in quantity, and adult stem cells are rare in mature tissues and methods have not yet been worked out. There are two problems with embryonic stem cells in tissue replacement therapy, if you’re trying to obtain new tissue. Another potential obstacle encountered by researchers engaging in embryonic stem cell research is the possibility that embryonic stem cells would not be compatible with patients and would therefore be rejected. When implanted into a tissue, embryonic stem cells tend to form tumors. In 1997 scientist reported that they had successfully isolated and cultured human embryonic stem cells a feature which had by passed researchers for almost twenty years. That announcement launched an intense and unrelenting debate between people who approve “ESCR” and the people who were against it.

No comments: