Final answer:
Neutrophils are primarily involved in phagocytosis, engulfing and digesting pathogens to protect the body from infections. They also produce cytokines that aid in the immune response.
Step-by-step explanation:
Neutrophils, which are polymorphonuclear leukocytes, play a crucial role in the body's immune response. Specifically, they are primarily involved in phagocytosis, a process where they engulf and digest invading pathogens. This action results in the death and removal of the pathogens, which prevents them from multiplying or creating toxic compounds that could harm human cells. Additionally, neutrophils produce large quantities of cytokines that promote the inflammatory response necessary for pathogen removal.