The immune system is your body’s defence against infection and illness. It is formed of a complex network of cells and proteins spread throughout the entire body. Your immune system has many components:
- Organs of the immune system, e.g. skin and mucous membranes, lymph nodes, bone marrow and thymus.
- Cellular components, e.g., lymphocytes and phagocytes
- Molecular components, e.g., antibodies