What Are the Functions of Red & White Blood Cells?

There are millions of red blood cells and between 7,000 and 25,000 white blood cells per drop of blood, according to the Franklin Institute. Although all blood cells develop in the bone marrow and enter the blood vessels to replenish existing cells as they die, red blood cells and white blood cells perform different functions.

Delivering Oxygen

• The red color of red blood cells is closely linked to one of their most important functions: delivering oxygen. Red blood cells, according to the Franklin Institute, contain hemoglobin, which in turn contains iron that produces the red color of these cells. Hemoglobin is used to transport oxygen obtained in the lungs to other areas of the body. To help blood cells accomplish this task, they have developed a flexible shape to get through very small spaces, according to the Puget Sound Blood Center.

Picking Up Waste

• While red blood cells bring oxygen to the rest of the cells, they use hemoglobin to collect waste gases, such as carbon dioxide, according to the Franklin Institute.

Fighting Infection

• While red blood cells carry out gas exchange in the body, white blood cells are dedicated to defense. They protect people from infection in many different ways, depending on the type of cell. The number of white blood cells increases to help fight off infection, according to the Franklin Institute.

  There are five different types of leukocytes (white blood cells). Lymphocytes stimulate antibodies to help target infections. Monocytes, such as macrophages, surround invaders and dissolve them, according to the Puget Sound Blood Center. Neutrophils perform a similar function, but can also call on other cells to attack an invader. Basophils and eosinophils are most closely associated with allergic response.