Risk and CVD

• What is atherosclerosis?

  The hardening of the arteries due to build up of plaque, which narrows the lumen
• what happens during an inflammatory response?

  Which blood cells leave blood and move into artery wall lining where they differentiate from monocytes to macrophages
• where is thromboplastin released from 


  released when a damage vessel has exposed collagen. Also released by platelets.
• what do thromboplastin and calcium ions do?

  activate plasma proteins, convert soluble protein prothrombin to enzyme thrombin
• what does thrombin do?

  Catalyses the conversion of fibrinogen into insoluble fibrin.
• how do fibrin fibers form the blood clot?

  tangle together forming a mesh. blood cells and platelets accumulate forming the clot.
• how can blood clots cause a myocardial infarction?

  They can narrow and eventually block the lumen of a coronary artery. This reduces the flow of oxygenated blood to heart muscle cells. Aerobic respiration is unable to occur as oxygen is required for the formation of ATP. Heart muscle cells begin to die.
• What is a stroke?

  Rapid loss of brain function due to disruption in oxygenated blood supply in the brain. This can occur due to a blood clot narrowing/ blocking arteries supplying blood to the brain. This results in reduced aerobic respiration.
• what is deep vein thrombosis?

  a blood clot which happens in a vein deep in the body and is often caused by inactivity which increases the risk of thrombosis
• what is angina? 


  Chest pain which is caused due to the narrowing of coronary arteries and therefore the reduced oxygenated blood supply to heart muscle.
• What can damage the endothelial lining

  High blood pressure, smoking (due to free radicals)
• How does age affect the risk of CVD?

  risk increases with age.

  -Artery lining becomes less elastic, therefore unable to expand to accommodate a higher blood volume so blood pressure increases. Increases blood pressure

  -plaque build up stiffens artery lining

  -free radical accumulation
• explain how high blood pressure increases the risk of CVD?

  High blood pressure causes damage to the endothelium lining of arteries

  This leads to an inflammatory response which leads to the build up of cholesterol under the lining, resulting in atheroma formation

  The plaque that develops narrows the lumen of the artery
• Explain how diet increases the risk of CVD

  A higher salt intake increases blood pressure which can cause damage to the endothelium of the artery, resulting in atheroma formation

  A higher saturated fat intake increases LDLs in the blood, which can cause accumulation of cholesterol under the artery lining, forming plaque/atheroma
• How does Carbon monoxide in smoke increases risk Of CVD?

  Attaches irreversibly to haemoglobin, reducing the oxygen carrying capacity of the blood.

  The blood therefore has a lower concentration of oxygen, reducing oxygen availability to tissues of heart. This increases CHD and heart attack
• how does nicotine in smoke increase risk of CVD?

  Increases blood pressure by stimulating adrenaline thus causing vasoconstriction and endothelial dysfunction. Heart rate increased.

  Increases aggregation/ stickiness of platelets, increasing blood clotting and therefore reducing oxygen and further increasing pressure.
• How does smoking increase CVD risk (free radicals and antioxidants)

  Smoking reduces the amount of antioxidants, which therefore increases amount of free radicals in blood. Damage to the endothelium is more likely.
• how do free radicals increase risk of CVD?

  Damage the endothelium lining

  oxidize LDLs, making cholesterol accumulation increase, increasing plaque formation.
• How does exercise reduce risk of CVD?

  -reduces heart rate as the heart is able to work less hard to pump the same a mount of blood.

  -increases the amount of HDL in the blood, increasing the HDL:LDL ratio. Risk of CVD is directly correlated to the HDL:LDL. Therefore cholesterol in blood is reduced.
• how do genetics increase risk of CVD?

  Some people are more likely to inherit alleles linking to high blood pressure or high cholesterol levels.
• What is risk? 


  A measure of the probability that damage to health will occur as a result of a particular hazard
• How can perception of risk be overestimated by people?

  Unfamiliar risk

  unnatural risk

  misleading information on the Risk

  the risk is not under their control
• Why can risk be underestimated?

  If the risk has a long-term effect

  if the risk is under their control

  familiarity with the risk
• Why are large Amounts of data needed in studies?

  Increases the validity of the experiment, in order to ensure Correlation is statistically significant
• What is correlation 


  Two factors are linked by statistical data. This does not always mean causation
• What is causation 


  When a change in one factor directly causes a change in another factor
• how is data described in answers

  -identify a trend

  -state what the data shows/ how it links to the question
• How is a conclusion drawn from data 


  draw a conclusion between the variables, such as stating what type of correlation there is.
• what is meant by validity of an experiment

  the experimental design accurately answers the question
• what factors increase validity?

  -larger sample size

  -a control in order to isolate the effects of the tested variable

  -controls all variables not tested

  -longer periods of time

  -multiple studies in order to ensure statistical significance, repetition. -directly measures variable
• How do we know if data is statistically significant 


  If the difference between the data of tested groups is large, it shows that this result Is not just by chance.
• how can error bars be used to determine statistical significance?

  if error bars overlap, the results are not statistically significant and more research/ repeats need to be done with a larger data set .
• why is data measured over longer periods of time more valid?

  can show the long term effects of the variable investigated.
• Why are larger data sets more valid?

  More accurately represent the population

  can be used to more accurately determine if results are statistically significant
• why are studies only testing certain ages less reliable?

  They can only be applied to people of that age range and the data cannot be extrapolated beyond that age
• How can we reduce bias in choosing samples and how does this improve experimental design?

  Bias can be reduced by randomly choosing participants.

  This improves experimental design as the sample is more likely to be representative of population.
• What is meant by a reliable test?

  the test can be repeated and yield similar results each time. If a study is reliable then this shows that the study is more valid.
• what is conflicting evidence?

  data collected shows a different pattern to other sets of data which may be due to uncontrolled factors.
• multiple studies are used to conclude causation of a risk factor and the disease.
• What is meta analysis?

  Multiple studies with similar design are analyzed together to make links between the data and the risk. A similar conclusion from these studies should be drawn in order to conclude correlation.