The Role of Bone Marrow

Keywords

Bones, marrow, myeloid tissue, fatty tissue, red bone marrow, yellow bone marrow, B-cells, T-cells, stem cells, mesenchymal cells, hematopoietic cells.

Introduction

Bone marrow is a soft spongy material that is inside some bones, including the hips and thigh bones.

What is Bone Marrow?

Bone marrow is a soft tissue that sits inside the centre of bones. There are two types of bone marrow:

• Red bone marrow: also known as myeloid tissue.
• Yellow bone marrow: known as fatty tissue.

Bone marrow also houses stem cells. These are cells that have no function. You can read more about them in the DNA section (find a link in the Related Pages section).

Facts about Bone Marrow

• Bone marrow creates most of the blood cells in our bodies - some 220 million a day.
• Red bone marrow contains tissue that has hematopoieticA rare, special type of cell controlled by cell division, death and differentiation. stem cells, which is where the blood cells are created.
• The yellow bone marrow create fat, cartilage and bone. They contain mesenchymalCells that have the ability to self-renew. stem cells.
• Stem cells are cells that have no function until given, and are often used with research for diseases and conditions such as forms of cancer.
• The reason bone marrow creates so many cells each day is because red blood cells only have a lifetime of 120 days.
• Bone marrow also creates white blood cells, and platelets.

Interesting fact: B-cells are so-called because they mature in the bone marrow, whereas T-cells are so-called because they mature in the Thymus gland.

So, bone marrow is quite important, even in our day-to-day life. Without it, we would not have enough blood cells in our cirulatory system. There are treatments for those that have issues with their bone marrow. Bone marrow transplants can be carried out, and can replace non-functioning bone marrow due to conditions such as leukemia or sickle cell anaemia.

Changes in Bone Marrow

As you get older, the bone marrow changes from having a lot of red marrow, which creates the blood cells, to having a lot of yellow marrow, which stores fats. Most bones in the body, and by the time you reach adulthood, will have yellow bone marrow in them, instead of red bone marrow.