Leukocytes, also known as white blood cells, are made up of several different types of cells, each with its own unique function in the immune system. Here's a breakdown:

1. Granulocytes:

* Neutrophils: The most abundant leukocyte, they engulf and destroy bacteria and fungi.

* Eosinophils: Involved in allergic reactions and defense against parasites.

* Basophils: Release histamine and other chemicals involved in inflammation and allergic reactions.

2. Agranulocytes:

* Lymphocytes:

* T lymphocytes (T cells): Play a key role in cell-mediated immunity, directly attacking infected cells or cancer cells.

* B lymphocytes (B cells): Responsible for antibody-mediated immunity, producing antibodies to target specific pathogens.

* Monocytes: Transform into macrophages, large phagocytic cells that engulf and destroy pathogens, cellular debris, and foreign particles.

In summary: Leukocytes are a diverse group of cells that work together to defend the body against infection, disease, and foreign invaders. They are essential for immune system function and overall health.