Definition

• Stem cells are types of cells within animal and human bodies that are unspecialized. That is, they have the capacity to develop into different types of tissues and organs. Stem cells can divide with limitless capacity within a living being. This ability to divide makes them very important in the repair process of damaged cells, tissues and organs. When stem cells divide, they can produce more stem cells or more specialized cells with specific body functions.
  
  

Types

• The two main types of stem cells are embryonic and nonembryonic. Embryonic stem cells are obtained from embryos. Human embryonic stem cells are gathered from embryos that were fertilized "in vitro"--that is, in a laboratory setting, not in a woman's body. Nonembryonic stem cells are also known as adult stem cells and somatic stem cells. These cells are found in various areas of the body among specialized cells. For instance, there are adult stem cells in the midst of specialized bone marrow cells. Adult stem cells function to repair damaged tissues around them.
  
  

Uses

• Scientists are researching how to stimulate embryonic stem cells and adult stem cells to become specific types of cells and tissues. This type of research has the potential to help people with a illnesses and injuries such as spinal cord injuries, diabetes, Parkinson's disease and muscular dystrophy. These diseases present a present problem because they do irreparable damage to various cells; however, with the use of stem cells, many researchers believe that there is the chance of creating new cells that will replace and/or repair the old ones. Understanding the way stem cells divide also may assist doctors and scientists in better understanding and treating diseases like cancer, in which cells divide in an uncontrolled manner.