| A | B |
|---|
| pathogens | An organism that causes disease |
| infectious disease | A disease that can pass from one organism to another |
| pasteurization | A heating process that is widely used to kill microorganisms in food products such as milk |
| phagocyte | A white blood cell that destroys pathogens by engulfing them and breaking them down |
| immune 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 the pathogen |
| T cells | A lymphocyte that identifies pathogens and distinguishes one pathogen from another |
| antigens | A molecule on a cell that the immune system can recognize either as part of the body or as coming from outside the body |
| B cells | A lymphocyte that produces chemicals that help destroy a specific kind of pathogen |
| antibody | A chemical produced by a B cell of the immune system that destroys a specific kind of pathogen |
| AIDS | (aquired immunodeficiency syndrome) A disease caused by a virus that attacks the immune system |
| Immunity | The ability of the immune system to destroy pathogens before the can cause disease |
| active immunity | Immunity that occurs when a person's own immune system produces antibodies in response to the presence of a pathogen |
| vaccination | The process by which harmless antigens are deliberately introduced into a person's body to produce active immunity |
| vaccine | A substance used in a vaccination that consists of pathogens that have been weakened or killed but can still trigger the immune system into action |
| antibiotic | A chemical that kills bacteria or slows their growth without harming the body cells of humans |
| Noninfectious diseases | A disease that is not spread from person to person |
| allergen | A substance that causes an allergy |
| histamine | A chemical that is responsible for the symptoms of allergy |
| asthma | A disorder in which the respiratory passages narrow significantly |
| insulin | A chemical produced in the pancreas that enables the body's cells to take in glucose from the blood and use it for energy |
| diabetes | A condition in which either the pancreas fails to produce enough insulin, or the body's cells can't use it properly |
| tumor | A mass of abnormal cells that develops when cancerous cells divide and grow uncontrollably |
| cancer | A disease in which some body cells grwo and divide uncontrollably, damaging the parts of the body around them |
| carcinogens | A substance or a factor in the environment that can cause cancer |
