Immunity is the capability of our body to defend against the microorganisms including bacteria, viruses, fungi, and parasites.


All cells, chemicals, and tissues acting together to offer immunity make up the immune system.

  • Examples of the cells are white blood cells, macrophages, neutrophils, etc.
  • Examples of the chemical substances are interleukins, major basic protein, interferon gamma, etc.
  • Examples of the tissues are bone marrow, thymus, lymph nodes, spleen, tonsils, etc.