Which type of white blood cells are known to be the largest?

Monocytes are indeed the largest type of white blood cells. These cells typically have a diameter of about 12 to 20 micrometers, making them stand out among other leukocytes. Their primary role in the immune system involves phagocytosis, where they engulf and digest pathogens and debris in the body. After circulating in the bloodstream for about one to three days, monocytes migrate into tissues, where they differentiate into macrophages or dendritic cells, both of which play essential roles in the immune response.

In contrast, lymphocytes, neutrophils, and eosinophils are smaller in size. Lymphocytes are crucial for adaptive immunity and are generally about 7 to 10 micrometers in diameter. Neutrophils, which are instrumental in the body's first line of defense against infections, measure around 10 to 12 micrometers. Eosinophils, involved primarily in combating parasitic infections and allergic reactions, are also similar in size to neutrophils. Thus, monocytes' size and functional capacity make them distinct from the other types of white blood cells.