Immune system
As a defense response, the immune system must detect a wide variety of agents and distinguish them from own healthy tissue. It needs to recognize and destroys foreign structures (viruses, bacteria, proteins, toxins, etc.) or own altered cells (tumor), altogether this is called the immune response. Thus, the immune system manifests itself as a defense of the body, but also on self-tolerance. Disorders of the immune system can result in autoimmune diseases (overactive immune responses), inflammatory diseases, immunodeficiencies, and cancer.The immune system can be classified into two basic subsystems – the innate immune system (nonspecific) and the adaptive/acquired immunity (specific).
In our body we have special organs and other components, which mediate the immune response: white blood cells, antibodies, the complement system, the lymphatic system, the spleen, the thymus, and the bone marrow.