1.3 Risk factors Flashcards
What is a cohort study?
following a large group of people overtime to see who develops the disease and who doesn’t.
what are case control studies?
a group of people with a disease are compared with a control group of individuals who do not have the disease. information is collected about the risk factors that they have previously been exposed to.
name four features of a good study?
representative sample
valid and reliable results
sample size
controlling variables
what are the six risk factors for CVD?
high blood pressure
obesity
blood cholesterol/dietary factors
smoking
inactivity
genetic inheritance
what is systolic pressure?
the pressure in an artery is highest during the phase of the cardiac cycle when the ventricles have contracted and forced blood into the arteries.
what is diastolic pressure?
when pressure is at its lowest in the artery when the ventricles are relaxed.
what measures blood pressure?
sphygmomanometer
what is pressure measured in, in medical practice?
millimetres of mercury (mmHg)
what is a healthy blood pressure?
100-140
————-
60-90
what are factors that cause arteries to constrict?
loss of elasticity with age
atherosclerosis
adrenaline
high salt diet
what are treatments for high blood pressure?
ACE inhibitors
calcium channel blockers
diuretics
beta blockers
what is oedema?
fluid building up in tissues and causing swelling
what is one calorie defined as?
the quantity of heat energy required to raise the temperature of 1cm^3 of water by 1 degrees celsius
what is the general formula of carbohydrates?
Cx(H2O)n
explain about bonding in sugars
either monosaccharides or disaccharides. condensation reactions are common in the formation of complex molecules and addition of water in a hydrolysis reaction splits the molecule
how does the structure of galactose differ from glucose?
the OH group on carbon 1 and 4 lies on the opposite side compared to glucose
what is the bond called between two single sugars units called?
glycosidic
what is sucrose formed from?
glucose and fructose
what is maltose formed from?
two glucose molecules
what is lactose formed from?
galactose and glucose
what are the three main types of polysaccharides found in food?
starch, cellulose and glycogen
what is starch made from?
amylose and amylopectin
what is amylose?
a straight chain of glucose molecules with 1,4 glycosidic bonds
what is amylopectin?
a polymer of glucose with side branches bonded with 1,6 glycosidic bonds holding the chains on
two characteristics of starch?
insoluble and has a spiral structure
what is the structure of glycogen?
glucose molecules with many side branches
what is the structure of cellulose?
straight chain of glucose
two characteristics of lipids?
insoluble in water but soluble in organic solvents and most are triglycerides
what are triglycerides made up of?
made up of three fatty acids and one glycerol molecule linked by condensation reactions
what kind and how many bonds are formed in triglycerides?
three ester bonds
what are saturated fats?
a chain containing the maximum number of hydrogens and no C-C double bonds
what are monounsaturated fats?
they have one double bond between two of the carbon atoms in each fatty acid chain
what are polyunsaturated fats?
they have a large number of double bonds
what does a double bond cause in the hydrocarbon change and how can this affect their state?
they cause a kink in the chain which increase the distance between molecules which weakens intermolecular forces and results in liquid oils at room temperature
how can unsaturated fats be made more solid at room temperature?
adding hydrogen to the double bonds making them saturated
two characteristics of cholesterol?
short lipid molecule and they are made in the liver from saturated fats
what is the difference between phospholipids and triglycerides?
in phospholipids one of the fatty acids is replaced by a negatively charged phosphate groip
what is the equation for BMI?
weight/height
why are lipoproteins needed?
cholesterol is not soluble in water so it is combined with proteins to become soluble so it can be transported in the bloodstream
what are HDLs and LDLs made from?
triglycerides, cholesterol and protein
what do LDLs do?
bind to receptor sites on the cell membrane
what do excess LDLs cause?
they overload the membrane receptors which may call LDL cholesterol to be deposited in the artery walls forming atheromas
what is the difference between LDLs and HDLs?
HDLs have a higher percentage of proteins
what does HDL do?
transport cholesterol from the body tissues to the liver where it’s broken down, lowers blood cholesterol levels and removes fatty plaques
how does saturated fats effect lipoproteins?
increases HDL and LDL but the increase in LDL is greater
name three consequences of smoking on the body?
1) carbon monoxide binds to haemoglobin which increases heart rate
2)nicotine stimulants adrenaline production which increases heart rate
3)chemicals damage the lining of the arteries
what gene cluster is associated with coronary heart disease?
apolipoprotein
what are apolipoproteins and what to they do?
they are the protein components of lipoproteins and stabilise the structure of the lipoproteins and recognise receptors involved in the lipoprotein uptake on the plasma membrane of cells
what does apolipoprotein A do?
the major protein in HDL so helps in the removal of cholesterol, mutations are association with low HDL levels
what does apolipoprotein B do?
the main protein in LDL so transfers cholesterol from blood to cells, mutation results in higher LDL levels
what does apolipoprotein E do?
a major component of HDL so removal of cholesterol
what are four factors in CHD development that aren’t genetic?
antioxidants, salt, stress and alcohol
how do antioxidants reduce the risk of CHD?
react with radicals that could cause damage to enzymes and genetic material which can cause cancer and heart disease
how does salt increase the risk of CHD?
a high salt diet causes the kidneys to retain water. high fluid levels in the blood cause high blood pressure
how does stress increase the risk of CHD?
the release of adrenaline causes arteries and artérioles to constrict which raises blood pressure
how does alcohol increase the risk of CHD?
it raises blood pressure, contributes to obesity and causes irregular heart beat. liver cells can be damaged which impairs its ability to remove glucose and lipids from the blood
