Bone marrow and stem cells

The full name for the stem cells in the blood and bone marrow is haemopoietic stem cells, but we shorten it to stem cells.

Bone marrow is a spongy material found inside the bones – particularly the bones of the pelvis. The bone marrow is where stem cells are made. Stem cells are blood cells at their earliest stage of development. All blood cells develop from stem cells.

The three main types of blood cells are:

• red blood cells, which carry oxygen to all cells in the body
• white blood cells, which are essential for fighting infection
• platelets, which help blood to clot and prevent bleeding.

When the cells are fully mature, they’re released into the bloodstream.

Stem cells are mainly found in the bone marrow. Doctors can stimulate a person’s stem cells to move from the bone marrow into their blood so they can be collected. They can do this by giving either injections of certain chemotherapy drugs| and proteins called growth factors| or with growth factors alone. This is called mobilising stem cells|.

Stem cells can then be collected from the blood. The stem cells are sometimes collected directly from the bone marrow.

Bone and bone marrow
View a large version of the image of the bone and bone marrow|