Adult Stem Cells and the Bone Marrow

If you've always wondered about how bone marrow creates adult stem cells, then this is the article for you. We'll look at the bone structure, the bone marrow and finally how adult stem cells are released. By the end, you'll have a great understanding of just what happens with adult stem cells and our bone marrow.
First, let's look at the bone structure. Many people believe the bones have very little blood circulation, but this is incorrect. There is voluminous blood flow and our bones contain both compact and spongy structure. The compact bone gives strength, while the spongy bone contains the marrow.
Next, let's look at the bone marrow itself. Ask anyone what color bone marrow is and they'll most likely say yellow. This is not completely true. Children have only red bone marrow, it's only as we age that the red marrow is displaced by fat storing yellow marrow. Adults still have red marrow in the ribs, vertebrae, pelvis and skull. This red marrow is where our adult stem cells are located and as we get less red marrow as we age, this explains the drop in stem cell production. It is estimated however, that our bone marrow contains around 150 million adult stem cells.
Finally, let's look at how bone marrow stem cells are released. Generally speaking in the body, cells divide through symmetrical division whereby a cell creates 2 identical cells which contain the original DNA. With the bone marrow however, asymmetrical division occurs. This is where a cell creates 2 different cells -- 1 with copies of the DNA and the other with the original DNA. The copied DNA stem cell leaves the bone marrow, while the original DNA stem cell remains behind. This process is known as immortal strand hypothesis and ensures the number of adult stem cells always remains constant in the bone marrow.
So there you have it, a short guide explaining how the bone marrow creates adult stem cells. We've looked at bone structure, the bone marrow and finally how adult stem cells are released from the bone marrow. The most important things to remember are that this process is natural but is reduced with age and that supporting the release of adult stem cells from the bone marrow will not reduce their numbers.