What Are Stem Cells?
Our bodies are made up of billions of cells each with their own specific function and purpose except for a type of cell known as stem cells. Stem cells are cells that have no defined purpose or function. They are able to renew themselves and become a diverse range of different cell types. They are found in nearly all multi-cellular organisms. There are different types of stem cells some that can become any other type of cell and some that can only become 1 or 2 other cell types. Stem cells act as a repair system for the body as they regenerate the cell type that is needed after damage has occurred. Stem cells are able to be manipulated by medical scientists to become specific cells that may be required such as insulin producing cells.
Where Do They Come From?
Stem cells can be harvested from two main sources, embryos and adult tissue. Stem cell research and use has been a controversial issue due to the use of embryonic stem cells (cells that come from unborn babies). These stem cells have been used due to their ability to become any type of cell required. The stem cells that are obtained come from 4 to 5 day old embryos that are in the blastocyst phase of development. The cells are taken from the inner cell mass. Most commonly these embryos are the extra embryos that are developed during the IVF process.
Adult stem cells are taken from a variety of places depending on why they are needed. Adult stem cells or somatic cells can be found in different types of tissue such as bone marrow, brain, blood, skeletal muscles, skin and the liver. These cells are thought to have less ability to differentiate into any type of cell and are more likely to regenerate into the tissue type from which they came.
Stem cells are now grown in laboratories to create specialized cells for the regeneration of muscle and nerves through cell culture. Highly adaptable stem cells that come from the umbilical cord and bone marrow are used commonly in medical therapies.