How does the immune system work?
The immune system is a vast network of cells, tissues, and organs that protect the body from billions of bacteria, viruses, and toxins. It relies on millions of defensive white blood cells that constantly screen the body for suspicious signs using cues called antigens.
These cues are detected by phagocytes, which trigger the immune response and send macrophages and dendritic cells to destroy any foreign cells they encounter.
The lymphocytes then orchestrate the defense, with T-cells searching and killing infected cells and B-cells and helper T-cells producing antibodies unique to the antigen.
These antibodies latch onto the invader and destroy it.
All of this leads to familiar symptoms such as high temperatures and swelling, which are actually processes designed to aid the immune response.
The immune response eradicates the threat within a few days and helps develop long-term immunity. However, some people have autoimmune diseases which trick the immune system into attacking the body's own healthy cells.