What do neutrophils form when they die in large numbers during infection?

When neutrophils die in large numbers during an infection, they primarily contribute to the formation of pus. Neutrophils are a type of white blood cell that plays a crucial role in the body's immune response, particularly by responding to sites of infection. After they fulfill their role in fighting pathogens, they undergo a process called apoptosis, or programmed cell death. The accumulation of these dead neutrophils, along with cellular debris, dead bacteria, and fluid, creates pus.

Pus typically appears as a thick, yellowish or greenish fluid, and its presence at an infection site often indicates an active immune response. This is why pus is often observed in conditions such as abscesses or infected wounds. Understanding this process highlights the body's mechanisms to localize and deal with infection while also indicating the intensity of the immune response to pathogens.