What role do white blood cells play in fighting infections?

White blood cells, or leukocytes, are the body's primary defence against infections, attacking and destroying harmful pathogens.

White blood cells are a crucial part of the immune system, which is the body's defence mechanism against disease-causing microorganisms, or pathogens. They are produced in the bone marrow and circulate in the bloodstream, ready to respond to any signs of infection or disease. There are several types of white blood cells, each with a specific role in the immune response.

Neutrophils, the most common type of white blood cells, are the first to arrive at the site of an infection. They engulf and destroy bacteria and fungi, a process known as phagocytosis. Eosinophils and basophils, on the other hand, are involved in combating parasitic infections and are also involved in allergic reactions.

Lymphocytes, another type of white blood cells, are responsible for the immune system's 'memory'. They recognise pathogens that the body has encountered before, enabling a faster and more effective response to subsequent infections. There are two types of lymphocytes: B cells, which produce antibodies that bind to pathogens and neutralise them, and T cells, which destroy infected cells.

Monocytes, the largest type of white blood cells, also perform phagocytosis. However, they also have another important role: they can develop into macrophages, large cells that can engulf and destroy large pathogens and cellular debris.

In summary, white blood cells are the body's main line of defence against infections. They detect, attack and destroy pathogens, and also remember previous infections to ensure a faster response in the future. Their diverse roles and abilities make them a vital part of the immune system.