What is the primary function of polymorphonuclear white blood cells?

The primary function of polymorphonuclear white blood cells, often referred to as neutrophils, is phagocytosis. Neutrophils are a critical component of the innate immune response and are one of the first responders to sites of infection or injury. Their main role is to engulf and digest pathogens such as bacteria and fungi, thereby contributing to the body’s defense mechanisms.

During phagocytosis, neutrophils recognize and bind to pathogens, then internalize and destroy them using various enzymes and reactive oxygen species. This process not only helps to eliminate infections but also plays a role in regulating further immune responses through the release of signaling molecules.

While other choices mention important immune functions such as antibody production, cytokine release, and cell signaling, these are not the primary functions of polymorphonuclear white blood cells. Antibody production is mainly performed by plasma cells derived from B lymphocytes. Cytokine release and cell signaling are functions associated more with other immune cells like lymphocytes and macrophages rather than being the primary role of neutrophils. Thus, the primary role of polymorphonuclear white blood cells is indeed phagocytosis.