Causes of disease

Question 1

Pathogens

Answer 1

Pathogens are micro-orgnanisms that cause disease, including bacteria, viruses and fungi. They cause disease by damaging the cells of the host and by producing toxins

Question 2

Disease

Answer 2

A description of physical or mental symptoms of a malfunction of the body or mind which result in an adverse effect on health. Disease can result from pathogens penetrating an organism’s interfaces with the environment

Question 3

Bodily interfaces with the environment

Answer 3

Common points of entry into the body, including the gas exchange system in the lungs and the digestive system in the small intestine

Question 4

Bacterial diseases

Answer 4

Diseases caused by bacteria multiplying within a host and producing toxins, e.g. cholera, TB. These toxins can inhibit enzymes, bind to cell receptors, bind to DNA, causing mutations, and can interfere with synapses

Question 5

Viral diseases

Answer 5

Diseases caused by viruses reproducing within the cells of the host, bursting them when they move on, e.g. influenza, HIV. Viruses use up cellular resources and prevent the cell from carrying out its normal reactions

Question 6

Infectious disease

Answer 6

Infectious diseases are caused by pathogenic organisms living in or on the body that cause harm. Disease must follow four steps: transmission, entrance, evasion and harming the host

Question 7

Transmission

Answer 7

Pathogens can be transmitted to their hosts by drinking water, eating food, breathing aerosol droplets, animal bites or direct contact

Question 8

Entrance

Answer 8

Pathogens can enter the body via cuts, abrasions and insect bites, as well as via exchange interfaces

Question 9

Evasion

Answer 9

Pathogens must evade the defences of the host, such as stomach acid, lysozyme enzymes and the immune system. However, when pathogens start to resist the defences, they can very quickly multiply and cause disease

Question 10

Risk

Answer 10

Risk is a measure of probability that damage to health will occur as a result of a given hazard, and it has two elements: the probability that a hazardous event will occur, and the consequences of that hazardous event

Question 11

Risk factor

Answer 11

A genetic trait or lifestyle choice which increases the risk of developing a disease or condition

Question 12

Risk factors for cancer

Answer 12

Smoking, including passive smoking; high-fat, low-fibre diets lacking in fruits and vegetables; obesity; lack of physical activity; increased exposure to sunlight (skin cancer); exposure to carcinogens

Question 13

Risk factors for Coronary Heart Disease

Answer 13

Smoking (2-6x more likely); high blood pressure, caused by prolonged stress, certain diets and a lack of exercise; blood cholesterol levels, caused by saturated fatty acids in the diet; obesity (BMI over 25); high-salt diet (increases blood pressure and cholesterol); lack of physical activity

Question 14

Correlation

Answer 14

A statistical relationship between to factors

Question 15

Causation

Answer 15

A scientific proof that a factor can lead to a condition