What is the main function of white blood cells in the body?

The main function of white blood cells, also known as leukocytes, is to defend the body against infections and foreign invaders. They play a crucial role in the immune system, identifying and attacking pathogens like bacteria, viruses, and fungi. White blood cells can also participate in the inflammatory response and help heal injuries by removing dead or damaged cells.

Each type of white blood cell has specialized functions; for instance, neutrophils target and consume bacteria, while lymphocytes are important for the adaptive immune response, remembering specific pathogens for faster response on subsequent exposures. This protective function is vital for maintaining health and preventing illnesses, which highlights their essential role in the body's defense mechanisms.

In contrast, transporting oxygen is primarily the role of red blood cells, while digesting food is managed by the digestive system and not by white blood cells. Carrying nutrients is also a function attributed to the blood but is specifically linked to plasma and red blood cells rather than the immune response facilitated by white blood cells.