Final answer:
The neutrophil is the leukocyte most involved in an acute inflammatory response, arriving first at the site of injury or infection and performing phagocytosis to eradicate pathogens.
Step-by-step explanation:
The leukocyte most involved in an acute inflammatory response is the neutrophil. Neutrophils are the most abundant white blood cells in the immune system and are the early responders to the site of infection or injury.
These cells respond to chemical signals and move towards the affected area through a process known as chemotaxis. Neutrophils are capable of phagocytosis, which is the engulfing and digesting of pathogens.
The changes in capillaries, which become more permeable during inflammation, are crucial because they allow leukocytes, including neutrophils, and fluids containing various defense substances to pass through the capillary walls to the site of injury or infection, contributing significantly to the inflammatory response.