1. Granulocytes:
* Neutrophils: The most abundant type, they are the first responders to infection and engulf and destroy bacteria.
* Eosinophils: Fight parasites and are involved in allergic reactions.
* Basophils: Release histamine and other chemicals involved in inflammation and allergic reactions.
2. Agranulocytes:
* Lymphocytes: These are involved in the immune response, specifically in recognizing and destroying specific pathogens. There are two main types:
* B lymphocytes (B cells): Produce antibodies to fight infection.
* T lymphocytes (T cells): Directly kill infected cells or help other immune cells.
* Monocytes: Larger cells that mature into macrophages, which engulf and destroy pathogens and cellular debris.
So, while you might think of "granulocytes" and "agranulocytes" as the two main types, it's more accurate to say there are five distinct types of white blood cells, each with their own unique function in the immune system.
