Neutrófilum

Neutrophils are a type of white blood cell, specifically a type of granulocyte, that play a central role in the innate immune system. They are characterized by multi-lobed nuclei (usually 2–5 lobes) and granules in their cytoplasm, which contain enzymes and antimicrobial proteins. The primary function of neutrophils is phagocytosis—the process of engulfing and destroying pathogens such as bacteria and fungi. Upon encountering an infection, neutrophils migrate to the site via chemotaxis (a response to chemical signals from damaged tissues or pathogens) and release antimicrobial substances from their granules, including defensins, cathelicidins, and proteases. This activity helps clear infections and contributes to inflammation. Neutrophils have a relatively short lifespan, typically 5–7 days in circulation, but they can rapidly accumulate at infection sites. Elevated levels of neutrophils in blood (neutrophilia) often indicate infection, inflammation, or stress, while low levels (neutropenia) may suggest immunodeficiency or bone marrow disorders. Overall, neutrophils are critical for the body's early defense against microbial threats and bridge innate and adaptive immune responses.