Edexcel Biology Gcse - Non-Communicable Diseases Part 4

Cancers are non-communicable diseases. This means they cannot be caught. Instead they develop. Cancers occur when cell division goes wrong. This causes cells to grow out of control, which form a tumour.

Cancers are looked for by doctors in a process called screening. This can be in an x-ray, in blood or urine tests or by using monoclonal antibodies.

Many cancers are caused by smoking or drinking too much. Others are caused by infections such as the HPV virus. Other causes include the Sun's UV rays and some environmental pollutants. The risk of cancer also increases as we get older.

chemotherapy

using chemicals to kill cancerous cells

radiotherapy

using x-rays to kill cancerous cells

palliative

this helps a person who has fatal cancer to die as comfortably as possible

Smoking damages the lining of the arteries, including the coronary arteries. The damage encourages the build-up of fatty material in the arteries. This can lead to a heart attack or a stroke.

Inhalation of carbon monoxide in cigarette smoke reduces the amount of oxygen that can be carried by the blood.

The nicotine in cigarette smoke increases heart rate, putting strain on the heart.

Chemicals in cigarette smoke increase the likelihood of the blood clotting, resulting in a heart attack or stroke.

smoking damages the bronchioles and can eventually destroy many of the alveoli in the lungs

the airways become inflamed and mucus, which normally traps particles in the lungs, builds up

the patient becomes breathless, and finds it more and more difficult to obtain the oxygen required for respiration

The damage caused by COPD is permanent. The disease cannot be cured, and can result in death. It is essential that the person seeks medical help to try to prevent progression of the disease.

The carcinogens in cigarette smoke also cause lung cancer. Almost all cases of lung cancer are caused by smoking - smaller numbers of cases are linked with air pollution and ionising radiation from radon gas, a radioactiveelement found in the environment in some parts of the country.

1) The patient begins by feeling sick, experiences weight loss and loss of appetite. There is a yellowing of the eyes, confusion, drowsiness and vomiting blood.

2) Alcohol causes lipids to build up in the liver which is called fatty liver disease.

3) Alcohol damage leads to alcoholic hepatitis, which can lead to death.

4) Cirrhosis of the liver can develop - the liver becomes scarred and loses its ability to function.

5) The changes are now irreversible and the reduced ability to process alcohol can also lead to brain damage.

slows reaction time

causes difficulty walking

can impair memory

causes slurred speech

causes changes in sleep patterns and mood, including increased anxiety and depression.

causes brain shrinkage

leads to memory problems

leads to psychiatric problems

may result in the patient requiring long-term care.

there is increased violence, antisocial behaviour and other crime associated with alcoholism

there is an increased risk of accidents

there is increased absence from work

alcoholism increases the likelihood of relationship break-up

alcoholism causes mental decline

alcoholism increases treatment costs to NHS

Obesity leads to high blood pressure and the build-up of fatty deposits in the arteries, which lead to cardiovascular disease. It also increases the likelihood of developing diabetes, another risk factor cardiovascular disease.

Being obese - with deposits of lipids in the abdomen - increases blood pressure beyond normal levels and increases levels of blood lipids.

Body fat also affects the body's ability to use insulin.

Type 2 diabetes is where the body's cells lose their sensitivity to insulin – they no longer respond, or respond less effectively, to the insulin that's produced.

Obesity accounts for 80 to 85 per cent of the risk of type 2 diabetes. Rising obesity is linked with 'western diet' - a diet that includes energy-rich 'fast foods' and an inactive lifestyle.

The risk of developing cardiovascular disease and type 2 diabetes can be reduced by eating a balanced diet, with unrefined, unprocessed, 'whole foods', and taking regular exercise.

weight (kg) / (height (m))^2

focus on certain groups and ignore others | - be affected by bias

the study must be wide, and cover all groups in the population being studied

the study must be random within these groups

between the sexes

resulting from people of different ages taking part

in people's lifestyles, which could affect the study

Analyses can be carried out on sub-sets of data within the whole study, so that comparisons can be made within the same age group, for instance.

In scientific studies, it may be difficult to control lifestyle factors that have the potential to affect the study, particularly if the study is long-term. People involved in a long-term study of the effects of alcohol intake, for instance, will have different lifestyle factors, for instance diet and exercise that could potentially affect the results of the study.

Bar charts show data collected for separate groups. The height of the bar is proportional to the measured number or frequency.

Note that the bars in a bar chart are all the same width. They do not touch each other as they show distinct categories.

Histograms look similar to bar charts, but show how the frequently data occur within certain ranges.

The independent variable is therefore continuous and is divided into sub-sections or classes.

The bars of a histogram are next to each other. The area of each bar is proportional to the frequency of each class interval. The bars of a histogram may not be the same width - it depends on the range they cover.

Line graphs display data where both variables are continuous.

With line graphs, you have a choice between connecting the plots point-to-point, or using a line of best fit.

Joining dots point to point is essential to show fluctuations in data - for instance, with the death rates - above - or a person's body temperature. We can also connect data point to point when we are confident of their quality.

A line of best fit looks at how variables behave in relation to each other - it is used to establish or display a correlation or a trend. These relationships may not be obvious from a table of data or could be obscured by experimental errors. Lines of best fit are also used to make predictions.