Lifestyle, Risk and Health

Question 1

Define an open circulatory system

Answer 1

A simple heart pumps blood between cavities. Blood circulates in open areas. Substances diffuse between blood and cells.

Question 2

Define a closed circulatory system.

Answer 2

Blood is enclosed within vessels, generating higher pressure. Blood travels from arteries to arterioles to capillaries and returns by venules to veins.

Question 3

Define a single circulatory system.

Answer 3

Carbon dioxide diffuses from blood out, oxygen diffuses into the blood.

Question 4

Define a double circulatory system.

Answer 4

Right ventricle pumps deoxygenated blood to the lungs, left ventricle pumps oxygenated blood round the body. Leads to a high metabolic rate.

Question 5

What are the properties of water that make it a good transport medium?

Answer 5

Water is polar as hydrogen is slightly positive and oxygen is slightly negative, forming a dipole. Other polar substances, as well as ionic and hydrophilic substances, can easily dissolve in water.

The specific heat capacity of water is very high to maintain homeostasis.

Water has a high boiling point due to the hydrogen bonds.

Question 6

Describe the structure of an artery.

Answer 6

Narrow lumen, thick walls, more collagen, smooth muscle and elastic fibres

Question 7

Describe the structure of a vein.

Answer 7

Wide lumen, thin walls, valves to prevent backflow.

Question 8

Describe the structure of a capillary

Answer 8

Endothelium is one cell thick, small lumen.

Question 9

Describe atrial systole.

Answer 9

High pressure. Atria fill with blood from the Vena Cava/Pulmonary Vein. Atrioventricular valves open. Blood flows into the ventricles. Atria contract.

Question 10

Describe ventricular systole.

Answer 10

High pressure. Ventricles fill with blood. Semi-lunar valves open, atrioventricular valves close. Ventricles contract.

Question 11

Describe diastole.

Answer 11

Low pressure. Atria and ventricles relax. Semi-lunar valves close. Coronary arteries fill.

Question 12

Describe atherosclerosis.

Answer 12

The endothelium becomes damaged. There is an inflammatory response causing white blood cells to move into the artery wall. A fatty deposit (atheroma) builds up. Calcium salts and fibrous tissues build up, causing a plaque. The artery loses elasticity, narrows and hardens. Causes a rise in blood pressure and dangerous positive feedback.

Question 13

Describe the consequences of atherosclerosis.

Answer 13

Increases chance of blood clots blocking the artery. Cells are permanently damaged. May result in heart attack, stroke, tissue death or gangrene. An artery may burst due to build up of blood.

Question 14

Describe the effects of Coronary Heart Disease.

Answer 14

Narrowed coronary arteries may lead to angina. Heart muscle lacks oxygen and has to respire anaerobically. Arteries blocked and are ischaemic (not enough blood flowing). If muscle cells are starved of oxygen for too long it results in an infarction.

Question 15

Describe the effects of a stroke.

Answer 15

If the supply of blood is interrupted, a stroke will happen. Blood clots blocking arteries may cause a stroke.

Question 16

Describe the clotting cascade reaction.

Answer 16

Platelets release the protein thromboplastin. This activates an enzyme which catalyses prothrombin into thrombin in the presence of Vitamin K and Ca2+ ions. This then catalyses soluble fibrinogen into insoluble fibrin. Fibrin traps platelets and red blood cells to form a clot.

Platelets in contact with damaged vessels become spheres instead of flattened discs. They stick to exposed collagen.

Question 17

Describe risk perception.

Answer 17

People will overestimate risk if:
it is out of their control
it is unnatural
it is unfamiliar
it is dreaded
it is unfair
or if the risk is very small.

Question 18

Describe some risk factors of CVD.

Answer 18

Age
Heredity
Physical environment
Social environment
Lifestyle
Behavioural choices.

Question 19

Define a cohort study.

Answer 19

Follows a large group of people over time to see who develops the disease in order to determine risk factors/the cause.

Question 20

Define a case-control study.

Answer 20

A group with the disease and a control group are compared to work out risk factors.

Question 21

What must a study have?

Answer 21

A clear aim
A representative, large sample
Controlled variables
Valid and reliable results.

Question 22

What is used to measure blood pressure?

Answer 22

A sphygomanometer.

Question 23

Describe oedema.

Answer 23

Fluid builds up in tissues leading to swelling. Higher blood pressure leads to more fluid being forced out of capillaries.

Question 24

How are disaccharides formed?

Answer 24

Monosaccharides are joined together in a condensation reaction, producing water. They are joined by a glycosidic bond. They can be split by hydrolysis.

Question 25

Describe the formation of starch.

Answer 25

Starch is made up of amylose, which is an unbranched chain, 1,4 glycosidic bonds and is cooked into a spiral, and amylopectin, which has side branches and 1,6 glycosidic bonds. Starch is low solubility in water and compact.

Question 26

Describe the formation of glycogen.

Answer 26

Made up of alpha glucose. Has numerous side branches allowing rapid hydrolysis. 1,4 and 1,6 glycosidic bonds. Stored in liver and muscles. Used by bacteria, fungi and animals as an energy store.

Question 27

Describe triglycerides.

Answer 27

Insoluble in water but soluble in organic solution.

Made up of a glycerol backbone and three fatty acid tails, linked by ester bonds in a condensation reaction producing three molecules of water.

Question 28

Describe the difference between saturated and unsaturated hydrocarbons.

Answer 28

Saturated hydrocarbons have the maximum number of hydrogens. They are straight, long chains with no double bonds. Solid at room temperature.

Unsaturated hydrocarbons have double bonds, causing links in the chain, preventing it from packing closely together. Liquids at room temperature. Hydrogenation can saturate, addition of hydrogens, uses a nickel catalyst.

Question 29

Describe low-density lipoproteins.

Answer 29

Triglycerides, proteins and cholesterol combine. Transports cholesterol to body cells. May be deposited in artery walls.

Excess LDLs overload membrane receptors.

Question 30

Describe high-density lipoproteins.

Answer 30

Triglycerides with a higher percentage of protein and a lower percentage of cholesterol. Transports cholesterol from body tissue to the liver, where it can be broken down. Lowers blood cholesterol levels and reduces plaques formed from atherosclerosis.

Question 31

Describe smoking as a risk factor.

Answer 31

Carbon monoxide binds to haemoglobin instead of oxygen, reducing the supply to cells, increasing heart rate.

Nicotine produces adrenaline, increases heart rate, causes arteries and arterioles to construct, raises blood pressure.

Chemicals in smoke damage endothelium of arteries.

Linked with reduced HDL.

Question 32

Describe the benefits of exercise.

Answer 32

Halves the risk of CHD.

Raises HDL cholesterol.

Reduces development chance of Type 2 diabetes.

Question 33

Describe the role of antioxidants.

Answer 33

Radicals are highly reactive and damage cells. Vitamins protect against this damage.

Question 34

Describe salt as a risk factor.

Answer 34

Kidneys retain water, higher fluid levels leads to higher blood pressure.

Question 35

Describe stress as a risk factor.

Answer 35

Releases adrenaline, arteries and arterioles constrict, raises blood pressure.

Question 36

Describe alcohol as a risk factor.

Answer 36

Leads to an irregular heartbeat, direct tissue damage, increases risk of CVD.

Moderate consumption linked with raised HDL levels.

Question 37

Describe Apolipoprotein A.

Answer 37

Major protein in HDL.

Mutation associated with low HDL and low removal of cholesterol.

Question 38

Describe Apolipoprotein B.

Answer 38

Main protein in LDL.

Mutation leads to higher levels of LDL and higher susceptibility to cardiovascular disease.

Question 39

Describe Apolipoprotein E.

Answer 39

Major protein in HDLs and vLDLs.

ApoE4 associated with slower removal of cholesterol and development of Alzheimer’s disease.

Question 40

Describe ACE inhibitors.

Answer 40

Antihypertensives.

Reduces synthesis of angiotensin II which causes vasoconstriction.

Reduces vasoconstriction which lowers blood pressure.

Question 41

Describe calcium channel blockers.

Answer 41

Antihypertensives. Block calcium channels in muscle cells.

Question 42

Describe diuretics.

Answer 42

Increases volume of urine. Decreases blood plasma volume and cardiac output, lowers blood pressure.

Question 43

Describe statins.

Answer 43

Inhibits an enzyme producing LDLs.

Question 44

Describe the use of aspirin as an anticoagulant.

Answer 44

Reduces the stickiness of platelets and the likelihood of clot formation.

Question 45

Describe the use of warfarin as an anticoagulant.

Answer 45

Interrupts production of Vitamin K and the synthesis of factors involved in clotting.

Question 46

Define basal metabolic rate.

Answer 46

The amount of energy used, per day, whilst at rest.

Question 47

Which two monosaccharides make sucrose?

Answer 47

Glucose and fructose.

Question 48

Which two monosaccharides make maltose?

Answer 48

Glucose and glucose.

Question 49

Which two monosaccharides make lactose?

Answer 49

Glucose and galactose.

Question 50

Describe obesity indicators.

Answer 50

BMI.

Waist to hip ratio.

Question 51

What is the calculation for waist to hip ratio.

Answer 51

Waist circumference divided by hip circumference.