,Immunology
• Can be defined as the study of a host’s reactions when fore
substances are introduced into the body.
• A foreign substance that induces such an immune response is ca
an immunogen .
• Immunology as a science has its roots in the study of immunity,
condition of being resistant to infection.
,Immunity
• All those physiological mechanisms that endow the animal with
capacity to recognize materials as foreign to itself and to neutra
eliminate or metabolize them with or without injury to its o
tissues.
• The immune system is structured to recognize, respond to,
destroy a wide variety of invading organism that would otherwise
capable of promoting infections, harmful to the body.
, Types of immunity
• NATURAL IMMUNITY: ability of an individual to res
infections by means of normally present body functions.
• ACQUIRED IMMUNITY: type of resistance that
characterized by specificity for each individual pathogen,
microbial agent.