Pathogens that invade the body may be engulfed by cells which carry out [blank_start]phagocytosis[blank_end]. The engulfed pathogen forms a vesicle known as a [blank_start]phagosome[blank_end]. Once engulfed the pathogen is broken down by enzymes called [blank_start]lysozymes[blank_end] released from organelles called [blank_start]lysosomes[blank_end].