White blood cells (WBCs), or leukocytes, are crucial in defending the body against infections and foreign invaders. Unlike red blood cells, which carry oxygen, white blood cells are involved in the immune response. They react to pathogens such as bacteria, viruses, and parasites.
White blood cells achieve this through various mechanisms that include attacking pathogens directly, producing antibodies, and signaling other cells in the immune system.
There are several types of white blood cells, each with specialized functions:
- Neutrophils: These are the most abundant, making up around 50-70% of white blood cells. They are the first responders to microbial infection.
- Lymphocytes: Comprising about 20-40%, they are responsible for antibody production and destroying infected cells.
- Monocytes: These contribute to 2-8% and play a role in breaking down bacteria.
- Eosinophils and Basophils: These are less abundant and involved in allergic reactions and parasitic infections.
By understanding how each type of white blood cell works, we can better appreciate how the body fights off disease.