What is the primary role of white blood cells?

The primary role of white blood cells, also known as leukocytes, is to protect the body against infections and foreign invaders. They are a crucial component of the immune system, which serves as the body’s defense mechanism. When pathogens such as bacteria, viruses, and other harmful entities enter the body, white blood cells respond by identifying, attacking, and destroying these threats. This process involves various types of white blood cells, each with specific functions, such as phagocytosis, antibody production, and the coordination of immune responses.

In contrast, the other options describe functions that do not pertain to white blood cells. For instance, the transportation of oxygen is primarily the function of red blood cells, which contain hemoglobin to carry oxygen from the lungs to tissues throughout the body. Regulating blood pressure involves complex interactions between various factors including blood vessel constriction and hormones, and is not managed by white blood cells. Finally, storing glucose is a function associated with the liver and muscle cells, which store glucose as glycogen, rather than being a role of the white blood cells. Thus, the correct understanding emphasizes the protective role of white blood cells in maintaining health and combating infections.