Bone marrow is that part of long bones and spongy bones in the medullar cavities which is highly vascular. It produces blood cells ranging from red cells to white cells and platelets. Hence, cellular, active bone marrow is referred to as red marrow. As an individual ages, the red marrow is turned into yellow marrow.
Red marrows are composed of quite a number of capillaries, red cells, white cells, platelets, little fat cells, lymphocytes, water and some minerals.
The red marrow contains both pluripotent stem cells and committed stem cells. The pluripotent cells have the ability to produce various cell types but the committed cells can produce only a fixed type of cell. However, committed cells are from pluripotent cells.
The red bone marrow's numerous functions go a long way in keeping us alive and healthy. The blood cells produced by the red marrow are the main proponents of these functions. The Red blood cells transport oxygen from one part of the body to another (childleuktrust.org.uk/treatment) , aiding cellular metabolism. They also carry nutrients and waste products from one part of the body to another. The white blood cells and lymphocytes help us ward off infections by attacking bacteria and alien substances in the body. Also, a functioning red bone marrow produces red blood cells in the required amounts. This prevents the disease state that is known as anaemia from occurring. Anaemia is a serious health condition when it occurs. When the blood cells are produced in optimal amounts, the systems in the body ranging from the metabolic, to the respiratory to the muscular and the reproductive systems.
References
(2010) Bone and Cartilage http://www.tutorvista.com/content/biology/biology-iv/locomotion-animals/bone-and-cartilage.php#
http://www.childleuktrust.org.uk/treatment.html