Final answer:
Neutrophils and monocytes migrate through the capillary wall to phagocytose pathogens as part of the body's immune response. Monocytes can differentiate into macrophages, and along with neutrophils, contribute to the innate immune defense against infections.
Step-by-step explanation:
Neutrophils and monocytes are types of white blood cells (WBCs) that play crucial roles in the body's immune response by phagocytosing pathogens. These cells are capable of squeezing through the capillary wall to reach and engulf pathogens in tissues. This process is known as extravasation or transendothelial migration. Monocytes can differentiate into macrophages in tissues, which are also key phagocytic cells that ingest and destroy pathogens, debris, and dead cells.
Neutrophils are particularly known for their phagocytic capabilities and can also release chemicals from their granules to destroy pathogens. This process is an important part of the innate immune response, providing a nonspecific defense against infections. Hence, for the statement in question, the correct fill-in-the-blank answer is 'capillary' wall, through which neutrophils and monocytes migrate to phagocytose pathogens.