Phagocytes are a crucial component of the innate immune system, responsible for the engulfment and destruction of pathogens such as bacteria and cellular debris. They utilize processes like phagocytosis, where pathogens are internalized into vesicles called phagosomes that fuse with lysosomes to degrade the ingested material. This mechanism provides a rapid and non-specific defense, limiting infection spread before adaptive immunity activates. Unlike lymphocytes, phagocytes do not produce antibodies or synthesize hormones. Their activity also helps initiate and modulate inflammatory responses by releasing cytokines.

Reference: Janeway's Immunobiology, Kenneth Murphy, 9th Edition.