A virus or microorganism that causes disease.
A disease that can pass from one organism to another.
A heating process that is widely used to kill microorganisms in food products such as milk.
Part of the body's defense against pathogens, in which white blood cells leak from the blood vessels into tissues; the white blood cells destroy pathogens by breaking them down.
A white blood cell that destroys pathogens by engulfing them and breaking them down.
An above-normal body temperature that is part of the inflammatory response.
Part of the body's defense against pathogens in which cells of the immune system react to each kind of pathogen with a defense targeted specifically at that pathogen.
A lymphocyte that identifies pathogens and distinguishes one pathogen from another.
A molecule on a cell that the immune system can recognize either as part of the body or as coming from outside the body.
A lymphocyte that produces a chemical that helps destroy a specific kind of pathogen.
A chemical produced by a B cell of the immune system that destroys a specific type of pathogen.
A disease caused by a virus that attacks the immune system.
The ability of the immune system to destroy pathogens before they can cause disease.
Immunity that occurs when a person's own immune system produces antibodies in response to the presence of a pathogen.
The process by which harmless antigens are deliberately introduced into a person's body to produce active immunity.
A substance used in a vaccination that consists of pathogens that have been weakened or killed but can still trigger the immune system.
Immunity in which the antibodies that fight a pathogen come from another organism rather than from a person's own body.
A chemical that kills bacteria or slows their growth without harming the body's cells.
A disease that is not spread from person to person.
A disorder in which the immune system is overly sensitive to a foreign substance.
A substance that causes an allergy.
A chemical that is responsible for the symptoms of an allergy.
A disorder in which the respiratory passages narrow significantly
A chemical produced in the pancreas that enables the body's cells to take in glucose from the blood and use it for energy.
A condition in which either the pancreas fails to produce enough insulin, or the body's cells cannot use insulin properly.
A mass of abnormal cells that develop when cancerous cells divide and grow uncontrollably.
A substance or factor in the environment that can cause cancer.