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

The primary function of white blood cells, also known as leukocytes, is to protect the body against infections and foreign invaders. They play a crucial role in the immune system by identifying, attacking, and destroying pathogens such as bacteria, viruses, and other harmful microorganisms. White blood cells are essential for the body's defense mechanisms, as they can recognize and remember specific pathogens, allowing for a more efficient immune response upon subsequent exposures.

In contrast to other functions such as transporting oxygen, which is primarily the role of red blood cells, or clotting blood, which involves platelets and certain proteins, white blood cells specifically focus on immune defense. Additionally, digesting food is primarily handled by the digestive system and involves organs such as the stomach and intestines, rather than the immune system. Understanding the specific functions of white blood cells highlights their importance in maintaining health and responding to infections.