Final answer:
Neutrophils die by apoptosis after phagocytosing pathogens at an infection site, leading to the formation of pus, which is a mix of dead neutrophils, pathogens, and other destroyed cells. These immune cells are essential in the body's initial defense against infection. Macrophages then clear the necrotic debris, furthering the healing process.
Step-by-step explanation:
Neutrophils are a type of white blood cell, specifically a rapid responder to the site of infection, acting as the body's first line of defense. These cells are highly efficient phagocytes with a propensity for attacking bacteria. Within the infected area, neutrophils execute their pathogen-fighting duties by releasing various toxic substances like lysozyme, hydrogen peroxide, and defensins that dismantle or obstruct bacterial and fungal cells.
Once neutrophils have engulfed pathogens through phagocytosis and have exhausted their lifespans, they undergo apoptosis and contribute to the pus accumulation at the site of infection. This pus is a visible collection of dead pathogens, spent neutrophils, tissue fluid, and potentially other local cells damaged in the process.
As an infection worsens or continues, more neutrophils are attracted to the infected site, increasing the volume of pus. Eventually, macrophages are also engaged, cleaning up the debris that includes the remains of neutrophils. High neutrophil counts can suggest an infection or inflammation, with their numbers rising significantly in response to certain stresses, such as burns, where a breach in the skin's barrier necessitates a heightened neutrophilic response to prevent further infection.