Topic 1- Lifestyle, Health And Risk Flashcards
What is cholesterol?
Cholesterol is a lipid found in the cell membrane which regulates fluidity.
What kind of structure does cholesterol have?
A steroid structure similar to testosterone and progesterone.
What is a lipoprotein?
A particles containing triglycerides and cholesterol surrounded by phospholipids and membrane.
What does LDL stand for?
Low density lipoprotein (bad cholesterol)
What does LDL do?
It transports cholesterol from the liver to tissues for the formation of membranes by binding to surface LDL receptors.
Why do high levels of LDL increase risk of atherosclerosis?
There are more LDL particles available than there are LDL receptors so LDL cholesterol cannot be removed from blood so more is deposited in blood vessels.
What is the difference between HDL and LDL structure?
HDL has unsaturated triglycerides whereas LDL has saturated.
What does HDL stand for?
High density lipoprotein (good cholesterol)
Why is HDL more dense?
Has a higher proportion of proteins than cholesterol
How does HDL reduce deposition of cholesterol in arteries?
By transporting it back to the liver for it to be destroyed.
What are the effects of saturated fats on cholesterol? (3)
- Increases LDL cholesterol
- Pushes HDL:LDL ratio in favour of LDL
- Reduces activity of LDL receptors so the cells are less able to remove LDL cholesterol from the blood
What is the solution to high blood cholesterol?
Replacing saturated fats with polyunsaturated fats which lower total blood cholesterol and decrease more LDL than HDL.
How much energy is once calorie worth?
The amount required to raise 1g of water by 1 degree Celsius
What do we need energy for? (7)
- Heart beat
- Digestion
- Movement
- Growth and repair
- Brain function
- Breathing
- Maintaining body temperature
What are the 8 factors that affect energy use?
- Temperature
- Exercise/ activity level
- Gender
- Illness/health
- Body composition
- Stress
- Age
- Pregnancy
Definition of basal metabolic rate?
Energy required to carry out basic functions to keep you alive.
What can the basal metabolic rate be affected by? (4)
- Age- older is less energy
- Weight- heavier is more
- Height- taller is more
- Biological gender
What happens when there is more energy in than out?
Excess energy is stored as fat and weight is gained
What happens when there is less energy in than out?
Body tissues is respired and weight is lost.
What does excessive weight gain lead to?
Obesity—> strains heart and circulatory system—-> increased risk of CVD
What are the 2 obesity indicators?
- BMI= weight (kg) divided by height2 (cm2). Doesn’t take into account body composition though so someone with high muscle mass may be wrongly deemed obese. >18 is underweight and 30+ is obese.
- Waist:hip ratio. Takes into account distribution of fat
What are the 5 things that overestimation of risk can be caused by?
- Media reports
- Overexposure to information
- Personal experience with risk or outcome
- Unfamiliarity
- The thing causes sever harm
What are the 6 things that can cause underestimation of risk?
- Lack of information
- Misunderstanding factors that increase risk
- Lack of personal experience
- Unfamiliarity
- Harm not being immediate
- Partaking in risk voluntarily
Definition of causation?
When the change in one variable causes a change in another.
What is an epidemiologist?
A scientist that studies patterns of disease.
What are the 2 risk factor studies?
Cohort and case control studies
What are cohort studies? (3)
- Are prospective which means no one starts with the disease.
- They follow large groups of people over a period of time and see who gets the disease
- Over this time, their exposure to risks are recorded and eventually correlations between risk factors and the diseases are made.
What is the evaluation of cohort studies? (2)
- Take many years
- Expensive
What are the 2 different types of cohort studies?
- One follows the general population and records the risks along the way.
- One uses 2 populations, one with a specific risk factor and the other without
What are case control studies? (3)
- They are retrospective which means that they look into the past
- They compare 2 groups of people, one with the disease and one without
- They then gather data on risk factors that they have been exposed to in the past and identify which risk factors contributed to the development of the disease.
What is the evaluation for case control studies? (2)
- Cheaper and faster
- Relies on reliable reporting from memory.
What are the 5 features of a good study?
- Good design
- Clear aim
- Must have large (1000+) and representative (non-biased) samples
- Must be valid- accurate measurements that measure what they claim to
- Must be reliable- collect same results when repeated.
What are the 9 risk factors for CVD?
- Smoking
- Age
- Genetics
- Gender
- Cholesterol levels
- Blood pressure
- Sedentary lifestyle
- Poor diet
- Stress
Why is smoking a risk factor for CVD?
It is addictive so hard to stop due to nicotine
Nicotine stimulates adrenaline production which:
1. Increases heart rate
2. Constricts arterioles
3. And both of these increase BP which is another risk factor.
It is also correlated with lower HDL
What are the other 2 chemicals in cigarettes?
- Tar/carcinogens:
- Damage artery walls so can lead to atherosclerosis - Carbon monoxide:
- Blocks oxygen from binding to haemoglobin which increases heart rate and blood pressure.
Why is age a risk factor for CVD? (3)
- Arteries become less elastic which causes blood pressure to increase
- You can drink when you are older which is another risk factor
- May be less able to exercise which increases risk
Why is genetics a risk factor for CVD? (2)
And what is the evaluation?
- Single gene inheritance e.g dominant allele for FH causes mutation in LDL receptor which decreases efficiency.
- Multiple genes cause most changes in risk e.g apolipoprotein genes A,B and E.
However, all these mutations are exacerbated or reduced by lifestyle choices.
So it is hard to determine the real effects of the mutations alone.
Why are cholesterol levels a risk factor for CVD? (2)
- High LDL levels increase risk
- Cholesterol forms part of an atheroma
Why is blood pressure a risk factor for CVD?
High blood pressure means damage to artery walls is more likely so there is a higher risk of atherosclerosis and atheromas.
It can also cause oedema which is swelling due to excess tissue fluid leaking from capillaries which then gets filtered by the lymph system.
What are the 4 factors that can elevate blood pressure?
- Stress
- Artery elasticity
- Weight
- High salt diet as water follows high salt concentration into the blood so the volume increase.
What are the 5 benefits to CVD of exercise?
- Prevents and can reduce high blood pressure
- Can help to maintain a healthy weight
- Increase levels of HDL without affecting LDL
- Increase chances of recovering from heart attack or stroke
- Increase efficiency of cardiovascular system and strength of heart muscle.
What are the 4 things included in poor diet?
- High salt levels
- can cause the kidney to retain water so increases blood pressure - Heavy alcohol consumption can:
- Increase blood pressure
- contributes to obesity
- can cause heart palpitations
- damages tissues like the brain, liver and heart
- Ethanol can end up in VLDL’s which increase risk of plaque formation. - No fruit or veg
- radicals are very reactive products made from chemical reactions in the body, antioxidants from vitamins in fruit and veg can help reduce them - Coffee
- Caffeine is a stimulant so increases heart rate and raises blood pressure
What is the benefit of moderate alcohol consumption?
Moderate consumption of red wine has been found to have a protective effect as correlations between increased HDL and red wine have been found.
Why is stress a risk factor of CVD?
Poor stress management has been linked to CVD.
It increases adrenaline which increases blood pressure
And can cause overeating, poor diet, drinking and smoking
