Describe the structure of leukocytes, name their functions.

White blood cells are part of our immune system. There are five different white blood cells that perform specific tasks based on their abilities and the type of invaders they are fighting. They are called neutrophils, basophils, eosinophils, monocytes, and lymphocytes. Neutrophils make up the largest number of white blood cells in the body. They travel through blood in search of their main goal. Basophils make up the smallest number of white blood cells in the body, but can have a large effect when activated. They are responsible for allergic reactions that cause asthma attacks, swelling and shortness of breath in some people. Eosinophils have many powerful functions, although they only target bacteria and parasites.