White blood cells, also known as leukocytes, play a crucial role in the body's defense against infections. There are several types of white blood cells, including neutrophils, lymphocytes, monocytes, eosinophils, and basophils, each with its own specific functions. Neutrophils are the most abundant type of white blood cells and are the first responders to infection. They can engulf and destroy pathogens through a process called phagocytosis. Lymphocytes, on the other hand, produce antibodies that help recognize and neutralize pathogens. Monocytes can differentiate into macrophages, which are responsible for engulfing and breaking down pathogens. Eosinophils are involved in fighting parasitic infections and allergic reactions, while basophils release histamine to trigger an inflammatory response. When the body is under attack from an infection, white blood cells are mobilized to the site of infection to help eliminate the pathogens. A high white blood cell count in a blood test can indicate an ongoing infection, while a low count may suggest a weakened immune system. In conclusion, white blood cells are essential components of the immune system and play a crucial role in protecting the body against infections. Understanding their functions can help us appreciate the complexity and sophistication of the body's defense mechanisms.