The module aims to examine the immunological processes that are essential to animal health. An overview of the innate and the adaptive immune system will be built upon in order to ensure an understanding of how the immune system responds to infection and disease. The aspects immunology that will be covered will include the organs of the immune system, the role of leukocytes, macrophages and the complement system. The structure and function of B cell antibodies (B lymphocytes) and T lymphocytes (cytotoxic and helper) will be analyzed in detail. The role of these cells and systems will then be explored in a selection of animals specifically investigating the immune response to bacteria, fungi, viruses and parasites. Finally autoimmune diseases will also be explored which occur when the immune system malfunctions and mounts an immune attack against its own tissues.