Description: Eosinophils are a type of white blood cell, specifically a type of leukocyte, that play a crucial role in the human immune system. They are characterized by their cytoplasm filled with granules that stain red or orange with eosin, an acidic dye. These granules contain various proteins and enzymes that are essential for combating infections, especially those caused by parasites, as well as for participating in allergic reactions. Eosinophils represent approximately 1% to 4% of white blood cells in the blood and are produced in the bone marrow. Their lifespan is relatively short, ranging from 8 to 12 hours in the bloodstream, although they can remain longer in tissues where they are needed. Eosinophil activation occurs in response to chemical signals indicating the presence of pathogens or allergens, allowing them to migrate to sites of inflammation. In addition to their role in defense against parasites, eosinophils are also involved in regulating the immune response and inflammation, making them an essential component of the immune system.
