Stem Cell Basics

Lear more about the different types of stem cells and where they come from!

What Are Stem Cells?

Stem Cells are unspecialized primary cells capable of becoming functioning cells in the body. They are the first, master cells formed in the embryo that turn into all the specialized cells needed to build the tissue and organs of the body. They are also found throughout the adult body, where they serve to repair and replace the tissue in which they’re located.

There are two basic types of stem cells that occur naturally, embryonic stem cells and adult stem cells. Embryonic Stem Cells are just what they sound like, the first cells that appear in a 3- to 5-day old embryo. They give rise to all of the specialized cell types that make up the tissue and organs of the body, from muscle and skin to heart and lungs.

Adult Stem cells are found in the tissue and organs of fully developed humans. They are found in virtually all tissue and organs, and have the power to divide without limit to replenish and repair the tissue and organs with new cells. In some organs, such as the skin or the gut, stem cells readily divide to repair or replace worn out and damaged tissue. In other organs, such as the lungs or heart, they divide only under certain conditions.


All stem cells have three distinguishing characteristics that make them unique. The first is that they are unspecialized cells. The second is that have the ability to renew themselves through cell division. The third is that they have the power to become specialized cells, thereby replacing specific types of dead or damaged cells.

For many decades now, scientists have been aware of both embryonic and adult stem cells. Their most important use until recently has been via bone marrow transplants, in which stem cells can recreate the blood-cell building marrow of a patient treated with radiation for blood cancers or severe autoimmune diseases.

In recent years whole new vistas of research and clinical treatments have emerged with the discovery that adult stem cells—in particular Mesenchymal Stem Cells—can be induced to become other kinds of cells. This is why scientists, researchers and doctors are so excited about stem cells—because they offer a natural way for the body to repair and rejuvenate itself. Because they can replenish and repair skin tissue, for example, stem cells are revolutionizing the practice of plastic surgery. Because they can repair and replace torn cartilage, for example, stem cells are being used instead of invasive orthopedic surgery. Because they can repair and replace muscle tissue, for example, stem cells are helping patients rejuvenate dead heart tissue following a heart attack.

This new field of medicine that uses stem cells is call cellular or regenerative medicine. It offers not only the potential to repair damaged tissue and organs, but to treat systemic diseases like diabetes and autoimmune disorders by replacing defective cells with healthy ones.