Infectious Diseases, Body Defense and HIV

pathogen

organisms that cause disease

infectious disease

a disease that is caused by the presence of a living thing within the body

toxin

poison produced by bacterial pathogens

Microorganism

living things too small to see without a microscope

Inflammatory response

fluid and white blood cells leak from blood vessels into nearby tissues. The WBC then fight the pathogens.

Phagocyte

WBC that engulfs pathogens and destroys them by breaking them down.

Immune response

Immune system cells react to each kind of pathogen with a defense targeted specifically at that pathogen.

lymphocyte

WBC that distinguish between different kinds of pathogens

T cell

identify pathogens

antigen

molecules that the immune system recognizes either as part of your body or as coming from outside your body.

B cell

produce proteins that help destroy pathogens

antibody

proteins produced by the B cells.

HIV

the only kind of virus known to attack the human immune system directly and destroy T cells

AIDS

disease caused by a virus that attacks the immune system.

Active Immunity

Immunity that occurs when a person’s own immune system produces antibodies in response to the presence of a pathogen

Antibiotic

A chemical that kills bacteria or slows their growth without harming body cells

Antibiotic resistance

The ability of bacteria to withstand the effects of an antibiotic

Immunity

The body’s ability to destroy pathogens before they can cause disease

Passive Immunity

Immunity in which antibodies are given to a person rather than produced within the person’s own body

Vaccination

The process by which harmless antigens are deliberately introduced into a person’s body to produce active immunity, also called immunization

Vaccine

A substance used in a vaccination