ADH and Epidemiological studies L.O: Answer a 6 mark question on ADH Explain the effects of alcohol and ecstasy on the release of ADH Explain correlation and cause using a 6 mark question Consider the impact of an epidemiological study

Circulatory system Blood vessels: Artery : large muscular wall small “lumen” high pressure Vein: thin muscular wall large lumen low pressure valves – prevent backflow Capillary: 1 cell thick – maximise diffusion Connects blood vessels to cells

Veins – deoxygenated blood – into heart Arteries – oxygenated blood – away from heart Double pump – pump blood to body and to lungs – provides extra pressure for blood to get to lungs Heart rate – no. of beats per minute – calculate using pulse rate – pulse of artery Blood pressure – pressure of blood on arterial wall – 2 values – higher value is when heart is cotracting, lower value is when heart is relaxing. Have a range of blood pressure values as people differ

High blood pressure – fatty deposits block arterial lumen – heart has to force blood under higher pressure – can cause heart attack Heart disease Stress – raises blood pressure Diet – high fat diet causes high cholesterol – fatty deposits in arteries – can break away and form blood clots, can block coronary artery and starve heart of oxygen Alcohol – raise blood pressure Illegal drugs – raise heart rate Smoking – nicotine – raises heart rate and CO – starves heart of oxygen

Exercise – reduces risk of heart disease Healthy diet - reduces risk of heart disease

Key question Why are you more likely to develop heart disease in an industrialised country (e.g. UK), compared to a non-industrialised country?

Correlation and cause Correlation is a relationship between factors Factors may affect an outcome E.g. Smoking and lung cancer Studies are carried out to see if there is a relationship between a factor and an outcome If an outcome happens when a factor is there, but not when it isn’t, scientists say there’s a correlation A correlation doesn’t prove one factor causes an outcome Correlation and cause not fully accepted until the underlying mechanism of cause is discovered e.g. smoking There might be another hidden factor that's affecting them both Maths e.g. Having big feet means you will be better at Maths Why is there a correlation between living in an industrialised country and an increased risk of heart disease?

Heart disease Mind map All factors you can associate with this term

6 mark question Toby reads an article that says that if you watch TV every day you will get heart disease. It says that there is a correlation between the amount of time you spend watching TV and the risk of dying from heart disease. He decides to stop watching TV because he believes it will cause heart disease. What advice would you give Toby about this?

that watching TV (the factor) causes heart disease (the outcome) idea that the factor might increase the probability of the outcome, but does not necessarily lead to it (does not make it certain to happen) Idea that watching TV means that Toby is inactive and this may increase the probability idea that other factor(s) may be just as important, or more important e.g. Toby might be able to / need to change other factors (to lower his risk of developing heart disease)

examples of other factors: genetic factors / family history of disease lifestyle factors, e.g. lack of exercise, poor/fatty diet, stress, smoking / excessive nicotine, drinking / excessive alcohol /high blood pressure/ high cholesterol accept economic factors if linked to poor diet etc.

Epidemiological studies Study of the patterns of disease and the factors that affect them Help to identify lifestyle risk factors Study a group of people who all died from heart disease and look for similarities in their lifestyle that may be linked to heart disease e.g. smokers Can also use studies to look at genetic factors, if you know enough about the genetic make-up of affected individuals

Write an article.... Explaining epidemiological studies Considering how to identify quality research Outlining the BRHS study Factors discovered from this study

Evaluate How useful do you think the study was to improve our understanding of the link between certain factors and heart disease?