Final answer:
Neutrophils, macrophages, and mast cells act as phagocytes.
Step-by-step explanation:
Neutrophils, macrophages, and mast cells act as phagocytes. These cells are part of the immune system and play a crucial role in engulfing and destroying pathogens during innate immune responses. Neutrophils are the most numerous type of phagocyte and are the first to arrive at the site of an infection. Macrophages are large phagocytic cells that develop from monocytes and are efficient in phagocytizing pathogens. Mast cells, although primarily known for their role in allergic reactions, also have phagocytic ability and play a part in clearing debris and pathogens.