where are white blood cells located in the body
White blood cells are cells of the immune system involved in defending the body against both infectious disease and foreign materials. Five diverse types of leukocytes exist, but they are all produced and derived from multipotent cells in the bone marrow known as a hematopoietic stem cells. They live for about 3 to 4 days in the average human body. Leukocytes are found throughout the body, including the blood and lymphatic system.