phagocytosis /fag′əsītō″sis/ [Gk, phagein + kytos + osis, condition] , the process by which certain cells engulf and destroy microorganisms and cellular debris. The process includes five steps: (1) invagination, (2) engulfment, (3) internalization and formation of the phagocyte vacuole, (4) fusing of lysosomes to digest the phagocytosed material, and (5) release of digested microbial products. −phagocytize, v.
