Translations:Immunsystem/2/en

The immune system is of great importance for the physical integrity of living beings, because practically all organisms are constantly exposed to the influences of the living environment; some of these influences pose a threat: If harmful microorganisms enter the body, this can lead to dysfunctions and diseases. Typical pathogens are: bacteria, and fungi, as well as unicellular (e.g. protozoa such as plasmodia) or multicellular parasites (e.g. tapeworms). Changes inside the body can also threaten the existence of a living being: If normal body cells lose their healthy function over time, they usually die and have to be degraded (necrosis) or degrade themselves (apoptosis). In rare cases they can also degenerate pathologically and lead to the development of cancer.