Neutrophils: First-Responder White Blood Cells

Neutrophils are the most abundant leukocytes (50–70% of circulating WBCs). They mature in bone marrow, circulate ~10 hours, then undergo apoptosis.

As phagocytes, they ingest and destroy microbes using reactive oxygen species and antimicrobial peptides. Their rapid response makes them the first line of defense.

Beyond pathogen clearance, neutrophils modulate inflammation and aid wound healing by releasing cytokines, growth factors, and tissue-remodeling enzymes.