White Blood Cells
- White blood cells are the body's defense against bacteria and viruses.
- In the bone marrow where they are produced, they outnumber red blood cells by 2 to 1.
- In the blood stream there are about 600 red blood cells for every white blood cell.
- There are many different types of white blood cells and each has a different function in fighting infection.
- White blood cells are bigger than red blood cells and can change shape easily.