Final answer:
Macrophages are changed to foam cells by engulfing lipoproteins. Foam cells release cytokines, including Interleukins, which stimulate the migration of smooth muscle cells.
Step-by-step explanation:
Macrophages are a type of white blood cell that plays a crucial role in the immune system. They are part of the innate immune system, which provides immediate and nonspecific defense against pathogens. Macrophages are phagocytes, meaning they are capable of engulfing and digesting foreign particles, such as bacteria, viruses, and cellular debris.
Macrophages are changed to foam cells by engulfing lipoproteins. As macrophages ingest excessive amounts of lipoproteins, they become bloated with lipids, transforming into foam cells. These foam cells release cytokines, including Interleukins, which stimulate the migration of smooth muscle cells.