Wednesday, December 8, 2010

What Is Leukemia? What Causes Leukemia?

The word Leukemia comes from the Greek leukos which means "white" and aima which means "blood". It is cancer of the blood or bone marrow (which produces blood cells). A person who has leukemia suffers from an abnormal production of blood cells, generally leukocytes (white blood cells).

The DNA of immature blood cells, mainly white cells, becomes damaged in some way. This abnormality causes the blood cells to grow and divide chaotically. Normal blood cells die after a while and are replaced by new cells which are produced in the bone marrow. The abnormal blood cells do not die so easily, and accumulate, occupying more and more space. As more and more space is occupied by these faulty blood cells there is less and less space for the normal cells - and the sufferer becomes ill. Quite simply, the bad cells crowd out the good cells in the blood.

In order to better understand what goes on we need to have a look at what the bone marrow does
 

Function of the bone marrow

The bone marrow is found in the inside of bones. The marrow in the large bones of adults produces blood cells. Approximately 4% of our total bodyweight consists of bone marrow.

There are two types of bone marrow: 1. Red marrow, made up mainly of myeloid tissue. 2. Yellow marrow, made up mostly of fat cells. Red marrow can be found in the flat bones, such as the breast bone, skull, vertebrae, shoulder blades, hip bone and ribs. Red marrow can also be found at the ends of long bones, such as the humerus and femur.

White blood cells (lymphocytes), red blood cells and platelets are produced in the red marrow. Red blood cells carry oxygen, white blood cells fight diseases. Platelets are essential for blood clotting. Yellow marrow can be found in the inside of the middle section of long bones.

If a person loses a lot of blood the body can convert yellow marrow to red marrow in order to raise blood cell production.

White blood cells, red blood cells and platelets exist in plasma - Blood plasma is the liquid component of blood, in which the blood cells are suspended.