What is the role of white blood cells?

White blood cells, or leukocytes, primarily function to protect the body against infections and diseases.

White blood cells are a crucial part of the immune system, which is the body's defence mechanism against harmful substances such as bacteria, viruses, fungi, and parasites. They are produced in the bone marrow and are found throughout the body, including the blood and lymphatic system. Unlike red blood cells, they are not confined to the circulatory system and can move freely into body tissues.

There are several types of white blood cells, each with a specific role in the immune response. Neutrophils, the most common type, are the first to arrive at the site of an infection and they engulf and destroy the invading microorganisms in a process called phagocytosis. Lymphocytes, another type, are responsible for the body's immune memory. They recognise and remember specific pathogens, allowing for a faster and more effective response if the same pathogen invades again in the future. Monocytes, which transform into macrophages when they reach the tissues, also perform phagocytosis but on a larger scale. They can ingest larger particles and are particularly effective against chronic infections.

Eosinophils and basophils, the less common types, are involved in the response to parasitic infections and allergic reactions. Eosinophils attack and kill parasites, while basophils release histamine, a chemical that causes inflammation and helps other white blood cells reach the site of infection more easily.

In addition to their role in fighting infections, white blood cells also play a role in inflammation, wound healing, and the removal of dead or damaged cells. They are a vital part of the body's defence system, working around the clock to keep us healthy.