What is the role of white blood cells in the human body?

White blood cells, also known as leukocytes, play a crucial role in the immune system of the human body. Their primary function is to defend against infections, diseases, and foreign invaders such as bacteria, viruses, and parasites. This defense mechanism is vital because it helps to maintain the body’s health and protects it from harmful pathogens that could lead to illness.

Different types of white blood cells have specific functions; for example, lymphocytes are essential for the adaptive immune response, while neutrophils are typically the first responders to sites of infection. When a pathogen is detected, these cells can either directly attack and destroy it or signal other components of the immune system to assist in the response. This intricate system ensures that the body can effectively identify and eliminate threats, underscoring the importance of white blood cells in maintaining overall health and immunity.

In contrast, transporting oxygen is primarily the function of red blood cells, metabolic processes are facilitated by various enzymes and substrates in the body, and body temperature regulation involves a complex interaction of the nervous system, the integumentary system (skin), and blood flow. Thus, these other options do not align with the role of white blood cells.