Final answer:
Neutrophils are the immune cells that are quickly produced and move to the site of an injury to attack foreign substances, playing an essential role in the body's immediate immune response.
Step-by-step explanation:
The cells that are rapidly produced to move to the site of an injury to attack foreign substances are neutrophils. Neutrophils are a type of leukocyte or white blood cell that plays a crucial role in the body's immune response. They are considered the first responders to infection and are highly efficient in phagocytosing, or engulfing, pathogens such as bacteria and fungi. Additionally, neutrophils produce cytokines, which are signaling molecules that help other phagocytes recognize and destroy pathogens, thereby purging them from the body. When a person is injured or has an infection, neutrophils are often the first immune cells to arrive at the scene where they can execute rapid response actions and release chemicals that further stimulate the inflammatory response.