Body Defence

Immunity

The body’s ability to fight infections of diseases caused by pathogens or any foreign matter.

Antibody

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

Pathogen

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

Antigen

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

The number of body line of defence

There are three lines of body defence

Immune response

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

The first line of defense

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

The second line of defence

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

The third line of defense

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

The action of antibodies is specific.

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

Biology

Question

Body Defence

Body Defence