A type of protein found on the surface of lymphocytes or a protein produced by lymphocytes and released into the blood plasma.

Microorganisms that cause disease, including bacteria, viruses and parasites.

Pathogens known as foreign substances enter the body and in turn stimulate the immune response.

There are three lines of body defence

The interaction between the antibody and the antigen causes the antigen to be destroyed

Consists of physical and chemical lines that prevent pathogens from entering the body.

The second line of defence is nonspecific and consists of fever, phagocytosis and inflammation.

Immune response by lymphocyte cells, if the pathogen successfully overcomes the second line of defence, this line of defence will be activated to act.

Each type of antibody can only combine with a specific antigen.