AAB Medical Technologist (MT) – Basic Knowledge Practice Exam Prep

White blood cells (WBCs), also known as leukocytes, play a crucial role in the immune system of the body. Their primary function is to defend the body against infections and foreign substances such as bacteria, viruses, parasites, and toxins. Each type of WBC has specific roles in identifying and eliminating pathogens. For example, neutrophils are often the first responders to sites of infection, while lymphocytes are critical for adaptive immunity, providing long-term protection through memory cells. This function is vital for maintaining health and preventing illness.

Other options involve different physiological functions. The transportation of nutrients throughout the body is typically handled by red blood cells and plasma in the circulatory system, while the clotting of blood is primarily the responsibility of platelets and certain clotting factors. Oxygen transport is carried out by red blood cells, which contain hemoglobin to bind oxygen molecules in the lungs and release them into the tissues. Each of these processes is important, but they do not represent the primary role of WBCs, which is centered on immune defense.