Final answer:
The process where cells migrate along a chemical gradient to attract immune cells is called chemotaxis, which is distinct from diapedesis and margination. Chemotaxis is crucial for immune response, guiding phagocytes to infected or injured areas where they can neutralize pathogens.
Step-by-step explanation:
The process in which cells migrate along a chemical gradient to attract immune system cells is known as chemotaxis. This directional movement enables phagocytes, such as macrophages, to move toward higher concentrations of chemical signals released by injured or infected tissue. Not to be confused with diapedesis, which is the process by which leukocytes squeeze through blood vessel walls to enter tissues, or margination, which is the initial step that leukocytes undergo when adhering to the blood vessel walls, chemotaxis is the subsequent movement responding to the chemical signals, enabling the immune response to target the precise locations of infection or injury.
Once leukocytes have exited the capillaries, they can be drawn to specific sites of infection or damage via positive chemotaxis by chemicals such as interleukins and other chemokines. Through this process, phagocytes can engulf and destroy pathogens, such as bacteria, utilizing enzymes and toxic compounds to break them down.