What is the typical lifespan of neutrophils?

Neutrophils, a type of white blood cell, play a crucial role in the immune system, particularly in fighting off infections. Their typical lifespan in circulation is approximately 6 to 8 hours. During this time, they patrol the bloodstream and migrate to sites of infection or inflammation, where they carry out their functions, such as phagocytosis of pathogens.

After fulfilling their role in the immune response, neutrophils can undergo programmed cell death, or apoptosis, if not activated fully or not needed, leading to clearance by macrophages. A lifespan of around 6 to 8 hours allows for a rapid response to infection while ensuring that they are effectively replaced by new neutrophils from the bone marrow, which continually produce them as part of maintaining the body's defense mechanisms.