What role do white blood cells have in the immune system?

White blood cells, or leukocytes, play a critical role in the immune system by identifying and destroying pathogens, such as bacteria, viruses, and other foreign substances. They are vital components of the body's defense mechanism against infections and diseases. When a pathogen is detected, specific types of white blood cells, like macrophages and lymphocytes, mobilize to the site of infection. Macrophages engulf and digest the pathogens, while lymphocytes, such as T-cells and B-cells, recognize specific antigens and mount targeted responses, which may include the production of antibodies.

This process is essential for maintaining health and homeostasis, as it enables the body to defend itself against various infections and diseases. The efficiency of white blood cells in this role is crucial in preventing illnesses and ensuring a swift response to immune challenges.