stem cell research facts

stem cell research facts



A mass in the abdomen and inserts a special instrument into the abdominal cavity. If these procedures do not yield enough tissue, more extensive diagnostic surgery may be necessary Stem cells are cells found in most, if not all, multi-cellular organisms. They are characterized by the ability to renew themselves through mitotic cell division and differentiating into a diverse range of specialized cell types. Research in the stem cell field grew out of findings by Canadian scientists Ernest A. McCulloch and James E. Till in the 1960s.[1][2] The two broad types of mammalian stem cells are: embryonic stem cells that are isolated from the inner cell mass of blastocysts, and adult stem cells that are found in adult tissues. In a developing embryo, stem cells can differentiate into all of the specialized embryonic tissues. In adult organisms, stem cells and progenitor cells act as a repair system for the body, replenishing specialized cells, but also maintain the normal turnover of regenerative organs, such as blood, skin, or intestinal tissues. The umbilical cord develops from and contains remnants of the yolk sac as the source of nutrients for the fetus. The cord is not directly connected to the mother's circulatory system, but instead joins the placenta, which transfers materials to and from the mother's blood without allowing direct mixing. The umbilical cord develops from and contains remnants of the yolk sac as the source of nutrients for the fetus. The cord is not directly connected to the mother's circulatory system, but instead joins the placenta, which transfers materials to and from the mother's blood without allowing direct mixing. The umbilical cord in a full term neonate is usually about 50 centimetres (20 in) long and about 2 centimetres (0.75 in) diameter. This diameter decreases rapidly within the placenta. Tumors that affect the abdominal cavity often do not cause symptoms until they are at a late stage. Symptoms include:

Stories Posted 2010/01 - AllAfrica.com
Stories Posted 2010/01 - AllAfrica.com