Stem-cell

Stem cells are cells that can differentiate into other types of cells and can divide to produce more of the same type of stem cells. They are found in multicellular organisms. In mammals, there are two broad types of stem cells: embryonic stem cells, which are isolated from the inner cell mass of blastocysts, and adult stem cells, which are found in various tissues. In adult organisms, stem cells and progenitor cells act as a repair system for the body, replenishing adult tissues. In a developing embryo, stem cells can differentiate into all the specialized cells—ectoderm, endoderm and mesoderm—but also maintain the normal turnover of regenerative organs, such as blood, skin, or intestinal tissues.

Types of stem cells[edit | edit source]

There are three types of stem cells: embryonic stem cells, adult stem cells, and induced pluripotent stem cells.

Embryonic stem cells[edit | edit source]

Embryonic stem cells come from a blastocyst that is 3–5 days old. When the sperm fertilizes the egg, it becomes a single cell that has the potential to form an entire organism. This cell and the first few cells it produces are totipotent.

Adult stem cells[edit | edit source]

Adult stem cells are found in small numbers in most adult tissues, such as bone marrow or fat. Compared with embryonic stem cells, adult stem cells have a more limited ability to give rise to various cells of the body.

Induced pluripotent stem cells[edit | edit source]

Induced pluripotent stem cells (iPSCs) are cells that have been engineered in the lab by converting tissue-specific cells, such as skin cells, into cells that behave like embryonic stem cells. iPSCs are a powerful tool for creating models of human disease.

Uses of stem cells[edit | edit source]

Stem cells have many uses in science and medicine. They can be used to study development by helping scientists to understand how a complex organism develops from a fertilized egg. Some serious medical conditions, such as cancer and birth defects, are due to problems that occur somewhere in this process. A better understanding of normal cell development will allow us to understand and perhaps correct the errors that cause these medical conditions.

See also[edit | edit source]

Stem-cell Resources
Need Help Finding a Doctor? Need help finding a doctor or specialist anywhere in the world? Explore our world directory. WikiMD's DocFinder can assist you in locating millions of physicians.	Medical Knowledge Access the latest research - Most recent articles Ongoing trials.