What are the types of blood cells?
All blood cells are produced from a small number of stem cells that are found in their highest concentration in the bone marrow. Peripheral blood stem cells circulate in blood vessels throughout the body. Stem cells represent only about one in a million cells in the bone marrow. The stem cells work like a “blood factory,” continually producing all types of new cells. The red blood cells, or erythrocytes, carry the oxygen necessary for life to all the body’s organs and tissues. Each red cell contains hemoglobin, which takes up oxygen as the blood passes through the lungs and releases it in the tissues. Platelets are cells that circulate in the blood and are essential for the prevention of abnormal bleeding. The white blood cells, or leukocytes, include the neutrophils, granulocytes, and lymphocytes. These cells play a major role in the body’s defense against bacteria, viruses, and fungi.
