Found in all multi-cellular organisms stem cells are characterized by their abilities to disperse into a wide range of specialized cell types and by the potential to renew themselves through mitotic cell divisions. Through cell cultures stem cells can also be grown under controlled environments into specialized cells with adult stem cells, including those derived from bone marrow and umbilical cord blood, routinely used in several medical treatments.
INNER CELL MASS:
Able to replicate themselves indefinately under defined conditions, and obtained from the inner cell mass of blastocysts, an early embryotic stage reached within the first five days of fertilization, stem cells maintain the potential to spread into the endoderm, mesoderm, and actoderm germ layers of such body parts as the nervous system, the epidermal tissues, the interior stomach lining, the lungs, the gastrointestinal tract, the muscles, the bones, the blood, and any of the more than two hundred and twenty cell types found in the human body, however, embryotic stem cells become an ethical issue because isolating the inner mass cell results in the death of the fertilized human embryo.
TOTIPOTENT STEM CELLS:
Coming from the joining of the egg to the sperm Totipotent Stem Cells can build complete organisms by separating into extraembryotic and embryotic cell types.
MULTIPOTENT STEM CELLS:
Multipotent Stem Cells can spread into several different types of cells that must be related to one another.
PLURIPOTENT STEM CELLS:
Coming from Totipotent Stem Cells, with the ability to enter all three germ layers and develop into any cell type, Pluripotent Stem Cells lack the potential to contribute to extraembryotic tissues.
OLIGOPOTENT STEM CELLS:
Obligopotent Stem Cells are myeloid or lymphoid cells that may become smooth muscle or endothelial cells.
UNIPOTENT STEM CELLS:
With the most common forms being skin cells, and hepatocysts in the main tissue of the liver’s cytoplasmic liquid between the cell membranes holding the organelles, a feature that may allow the liver to regrow itself from as little as twenty-five percent of its original mass, Unipotent Stem Cells produce only one cell type, their own.
STEM CELL THERAPIES:
Studied extensively some medical researchers believe that stem cell therapies can dramatically change the treatment of human diseases, as is currently being done with bone marrow transplants for lukemia patients, with the desire to use them in the treatment of Lou Gehrig’s Disease, spinal cord injuries, Parkinson’s Disease, Amyotrophic Lateral Sclerosis, and numerous other ailments.
Concerns about stem cell therapies include the potential risk of tumor formations from the transplanted stem cells, concerns caused by the stem cell’s uncontrollable divisions, the realistically significant potential of stem cell treatments, using excess(?) in vitro fertilization-created embryos for research, iPS cells as a bypass to the legal controversy of stem cells, and mutations.
This Article was compiled from several websites that provide much more information about stem cells including: