40.2 The Immune System

Immunity

• Ability of the body to resist a specific pathogen.

Inflammatory Response

• Nonspecific defense reaction to tissue damage caused by injury or infection.

Fever

• Elevated body temperature that occurs in response to infection.

Interferon

• One of a group of proteins that helps cells resist viral infection.

Immune Response

• The body’s specific defenses that attack a disease-causing agent.

Antigen

• Substance that triggers an immune response.

Humoral Immunity

• Immunity against antigens and pathogens in the body fluids.

Cell-Mediated Immunity

• Immunity against abnormal cells and pathogens inside living cells.

Antibody

• Protein that helps destroy pathogens.

Vaccination

• Injection of a weakened or mild form of a pathogen to produce immunity.

Active Immunity

• Immunity produced by exposure to an antigen, as a result of the immune response.

Passive Immunity

• Short-term immunity caused when antibodies produced by other animals for a pathogen are injected into the body.

Key Concept

• The function of the immune system is to fight infection through the production of cells that inactivate foreign substances or cells.

Key Concept

• Your body’s most important nonspecific defense is the skin.

Key Concept

• The inflammatory response is a nonspecific defense reaction to tissue damage caused by injury or infection.