Stem Cell
... bone marrow, blood, the eye, brain, skeletal muscle, dental pulp, liver, skin, the lining of the gastrointestinal tract, and pancreas. It is believed, through studies, which some adult cells are multipotent, meaning that a stem cell can give rise to other cells. For example, stem cells found in bone marrow can give rise to three major brain cells. Adult stem cells are rare to find, difficult to identify and purify, and difficult to maintain in the same state. Embryonic stem cells are derived from an early-stage embryo. The sperm fertilizes the ovum and results in a zygote. The zygote begins to divide about 30 hours after fertilization and by the third-to-fourth day, the embryo is a compact ball of 12 or more cells known as the morula. Five-to-six days after fertilization, and after several more cycles of cell division, the morula cells begin to specialize, forming a hollow sphere of cells, called a blastocyst. The outer layer of the blastocyst is called the trophoblast and the cluster of cells inside the sphere is called the inner cell mass. At this stage, there are more about 70 trophoblast cells and about 30 cells in the inner cell mass. The cells of the inner cell mass are multipotent stem cells that give rise to all cell types of the tissue layers of the embryo. In the last 3 years, it has become possible to remove these stem cells from the blastocyst and maintain them in the same state in cell culture lines in the laboratory. So that these stem cells can be used for medical therapies, cultured embryonic stem cells will need to be changed in their characteristics into appropriate tissues for transplantation into patients. Why is stem cell research important? By growing stem cells in labs scientists hope to regenerate specific tissue such as heart, lung and kidney tissue. This will help repair diseased or damaged organs or provide alternatives to organ transplant. So just imagine instead of getting and organ transplant, doctors can just use the stem cells to repair the damaged organs. Some diseases that stem cell therapy may cure are...