How White Blood Cells Are Formed
Our body is constantly making new blood cells. Billions of white blood cells, red blood cells, and platelets are produced every day to replace older cells that die either during normal processes, or because of illness.
This process by which new blood cells are created is called hematopoiesis.
Blood cells in the body, including the white cells, are made in the bone marrow, which is the soft spongy material in the center of the bones.
Blood cells are created from a group of "master cells" called stem cells, which also live within the bone marrow.
These stem cells have the ability to divide and produce all the different types of blood cells.
The white blood cells are an important part of our body's immune system.
Granulocytes are a special group of white blood cells that play an extremely important role in protecting the body against infections.
Neutrophils are a special class of granulocytes that are able to chase, engulf, and digest the bacteria that can cause infections.
Neutrophil development in the bone marrow takes approximately 10 days. Mature neutrophils are released into the blood where they survive for only 3 to 6 hours.
Because mature neutrophils are so short-lived, the bone marrow constantly produces large numbers of neutrophils to meet the body's needs.
Our body makes natural proteins that can signal the stem cell to start making cells that will eventually develop as neutrophils. One of the important proteins in this process is called granulocyte colony-stimulating factor or G-CSF.
The G-CSF protein can work on the cells in the bone marrow that eventually become neutrophils and signal that they should start becoming neutrophils.
The entire process by which stem cells develop into mature neutrophils can take about 10 days and includes 2 phases.
During the first phase, the stem cells and their off spring can divide as they develop and mature; this step takes about 6 days.
Then, over another 4 to 5 days, the cells mature further, however, the cells can no longer divide.
The mature neutrophils are finally released into the blood ...
... where they can fight bacteria and protect the body from infection.