Disease and immunity

Active immunity

Resistance in an organism developed through the production of specific antibodies in response to a pathogen.

Antibodies

Proteins produced by white blood cells in response to a specific antigen, triggering an immune response.

Antigen

A unique chemical present on the surface of a cell that induces an immune response.

Autoimmune disease

A disease in which the immune system targets and destroys its own healthy body cells.

Chemical barrier

A non-specific defense that destroys invading pathogens, e.g. mucus, stomach acid.

Host

The organism from which a pathogen or parasite obtains nutrients and/or shelter.

Mechanical barrier

A non-specific defense that physically blocks the entry of a pathogen, e.g. skin, nose hairs.

Memory cell

A type of white blood cell that provides immunological memory to a specific antigen on a pathogen.

Passive immunity

Resistance acquired via the transfer of antibodies, e.g. mother to infant by breastfeeding.

Pathogen

A disease-causing organism, e.g. virus, fungus, bacterium, protist.

Phagocytosis

The process by which white blood cells engulf and destroy pathogens.

Transmissible disease

A disease caused by a pathogen that can be spread between hosts.

Type 1 diabetes

A type of diabetes in which the pancreas fails to produce enough insulin, considered an autoimmune disease.

Vaccination

The deliberate exposure to a harmless pathogen to provide active immunity.

Water treatment

Any process that improves water quality and ensures it is not contaminated by disease-causing bacteria.

White blood cells

Cells of the immune system that protect the body from invading pathogens.

Addiction

Uncontrolled behavior associated with the inability to stop doing something or using a harmful substance.

Alcohol

A depressant drug that slows impulse transmission at synapses, increasing reaction times.

Anabolic steroids

Performance-enhancing drugs similar to testosterone, used illegally by athletes.

Antibiotic

A chemical produced by a living organism that kills or prevents the growth of bacteria.

Antibiotic-resistant bacteria

Bacteria that mutate to survive and reproduce despite antibiotic presence.

Cancer

A non-communicable disease caused by uncontrolled cell growth and division.

Carbon monoxide

A chemical in cigarette smoke that lowers red blood cells' ability to carry oxygen.

Chronic bronchitis

A respiratory disease caused by tar deposition leading to inflammation and mucus build-up.

Chronic obstructive pulmonary disease (COPD)

A group of lung conditions causing breathing difficulties.

Cirrhosis

Scarring of the liver tissue resulting from toxic breakdown products of alcohol.

Coronary heart disease

A disease caused by fatty deposits in coronary arteries, reducing blood flow to the heart.

Drug

A substance that alters the body’s chemical reactions.

Emphysema

A respiratory disease caused by the breakdown of alveoli due to tobacco smoke.

Heroin

An illegal depressant drug that stimulates dopamine release.

Lung cancer

A disease caused by carcinogens in tobacco smoke, leading to tumors and respiratory symptoms.

MRSA

A type of antibiotic-resistant bacteria commonly found in hospitals.

Nicotine

An addictive chemical in cigarette smoke that increases heart rate and blood pressure.

Tar

A carcinogen in tobacco smoke that causes airway inflammation and excess mucus production.

Testosterone

A male sex hormone involved in the development of male secondary sexual characteristics.

Tobacco smoke

Cigarette smoke that damages cilia and causes mucus buildup.

Withdrawal symptoms

Physical effects following the cessation of an addictive drug.