Topic 1: Lifestyle, Health And Risks

Question 0

What is a closed circulatory system, what are the variations and were can they be found?

Answer 0

A system with blood vessels. Double circulatory system is when blood travels through the heart twice, such as in humans. Single circulatory system is when the blood only goes through the heart once such as in fish.

Question 1

What is an open circulatory system and where can it be found?

Answer 1

No arteries, veins or capillaries. Can be found in small animals or insects, carries blood close to cells and organs to allow for diffusion

Question 2

What is mass flow?

Answer 2

Heart or tube contractions causing a change in blood pressure allowing blood to circulate around the body. Needed when diffusion is insufficient. Makes sure blood flows in the right direction. Fast transportation.

Question 3

Why do animals have a heart and circulatory system?

Answer 3

Small SA to Vol ratio so cannot diffuse from oxygen from skin. Blood vessels take blood close to cells to allow for diffusion, forming a circulatory system. The heart contracts to pressurise blood around the system

Question 4

What is diffusion?

Answer 4

Diffusion only occurs over small distances with animals with a large SA to vol ratio. It is the transportation of oxygen into a cell

Question 5

What is pulmonary circulation?

Answer 5

Portion of the cardiovascular system which carries deoxygenated blood to lungs and oxygenated blood to the heart. Low pressure.

Question 6

What is systemic circulation?

Answer 6

Carries oxygenated blood to the body and returns deoxygenated blood to the heart. High pressure.

Question 7

List the components of blood and their function

Answer 7

RBC - 40% of blood, carry oxygen to tissues and carbon dioxide away
WBC - 1%, first to respond to immune system, destroys old RBC, foreign matter e.g dust, bacteria, viruses, fungi
Platelets: form blood clots
Plasma: 55%, carries cells in blood, supplies nourishment removes waste

Question 8

What is the structure of a water molecule and it’s useful properties?

Answer 8

Polar molecule
2 H bonded to O
O is the negative side
2H are positive
Conducts heat slowly
Evaporates at high temperatures

Question 9

Why does water being polar mean it is a useful solvent?

Answer 9

It is able to encase both + and - ions, this means lots of substances can dissolve in it

Question 10

Structure of a capillary

Answer 10

4-10 nanometers thick meaning it slows 8 nanometer thick blood cells to allow for maximum oxygen exchange. Walls are one cell thick and have pores for water and dissolved substances. Pores allow small molecules through but stop plasma and proteins entering.

Question 11

Structure of an artery

Answer 11

Arteries have thick walls to sustain pressure. Middle layer is elastic fibres allowing for pulse and recoil. Further from the heart arteries are thinner with smooth muscle fibres in them to allow them to vasoconstrict or vasodilate. Artrioles are small arteries.

Question 12

Structure of a vein

Answer 12

Thin walls with less smooth muscle and elastic fibres in mid layers. The wall is thinner with a bigger diameter. Semi lunar valves stop backflow. Venules drain deoxidised blood from capillaries into veins.

Question 13

State the journey deoxidised blood would take through the heart

Answer 13

Venacarva, right atrium, atrioventricular valve, right ventricle, semi lunar valve, pulmary arter, lungs, pulmary vein, left atrium, atrioventricular valve, left ventricle, semilunar valve, aorta

Question 14

What happens during atrial and ventricular diastole?

Answer 14

Blood flows into atria, elastic recoil of atrial walls generates low pressure in atria drawing blood into to the heart.
Initially atrioventricular valves are open.
As ventricles relax blood draws from aorta and pulmonary artery closing SL valves (second heart sound dub).

Question 15

What happens during atrial systole?

Answer 15

As atria fill with blood, pressure increases, AV valves are pushed open, blood flows to relaxing ventricles. The two atria simultaneously contract forcing all blood into ventricles.

Question 16

What happens during ventricular systole?

Answer 16

Ventricles contract, increasing pressure in ventricles so the atrioventricular valves close (causing first heart sound lub). Blood is forced into the aorta and pulmary artery, semi lunar vales open. Blood begins to flow into relaxing atria.

Question 17

Why are ventricle walls thicker than atrium walls?

Answer 17

Ventricular walls have to withstand more pressure than the atrium walls, as they must push blood through valves. this is also why the left ventricle wall is thicker than the right

Question 18

Why do valves in the hear open/close?

Answer 18

This is due to pressure. When the heart contracts vales are pushed open, then the heart relaxes valves are pulled shut, they are supported my tendons stopping them from folding into the atria

Question 19

Define myocardial infraction?

Answer 19

Death to areas of cardiac muscle AKA a heart attack

Question 20

Define angina

Answer 20

Pain in the chest region due to a blockage in the conary arteries supplying the heart with oxygen

Question 21

Define stroke

Answer 21

Cause by lack of oxygen I the brain, causing sudden death to brain cells. AKA aneurysm or cerebrovascular accident (CVA)

Question 22

Define thrombosis

Answer 22

The formation of blood clots in vessel

Question 23

What is an atheroma, how does it turn into plaque?

Answer 23

Atheroma is a build up of fatty material which occurs in the lining wall causing the lumen to narrow, calcium salts and fibrous tissue build in the region forming plaque. This process is known as atherosclerosis

Question 24

Step by step of atherosclerosis

Answer 24

Artery wall damaged, inflammatory response, large WBCs enter wall, cholesterol accumulates, atheroma forms, calcium salts and fiberous tissue accumulate, hard plaque forms, wall elasticity reduced, arteries narrow, rising blood pressure, plaque breaks the endothelium causing blood clot (thrombosis) further rising blood pressure, increasing chances of plaque, cycle, atherosclerosis

Question 25

Step by step of blood clotting

Answer 25

Platelets In contact with damaged endothelium, platelets become sticky, platelet plug forms. Cascade of chemical changes, prothrombin, thrombin, fibrinogen, fibrin, tangled mesh, blood cells trapped, blood clot forms

Question 26

Define risk

Answer 26

The probability of occurrence of an unwanted outcome

Question 27

Define correlation

Answer 27

A change in one of the variables is reflected by a change in another variable

Question 28

Define causation

Answer 28

A change in a variable is responsible for a change in another variable

Question 29

What can cause chance of risks to be misinterpreted?

Answer 29

If they are: Sudden, uncontrollable, unfamiliar, unfair, small, slow

Question 30

Advantages and disadvantages of case control studies and cohort studies

Answer 30

``` CC: + fast, cheap - not as accurate, allows biased Cohort: + very accurate, very representative - long time, expensive ```

Question 31

What are the three key features of a good study?

Answer 31

Clear aim: appropriate to stated hypothesis which is reliable and useful Representative sample: studies must have representative sample to studies population Valid and reliable results: measuring what is useful for the study with good equipment for accuracy and repeats for reliability

Question 32

Factors which increase risk of cardio vascular disease (CVD) and why

Answer 32

``` Increasing age (heart grows weak) Tobacco smoke (over 2x the risk) Gender (men produce less HDL) High blood pressure (stress on heart) Genetics (history of CVD) Diet (plus LDL cholesterol levels) Inactivity (exercise lowers cholesterol) ```

Question 33

How can high blood pressure lead to CVD?

Answer 33

Increased risk of endothelium damage, high BP means more cholesterol will be deposited and more fibrogen to form blood clots. If blood clots are left for too long they will cause CVD

Question 34

Define hypertension

Answer 34

Bloody pressure is permanently high

Question 35

Define systolic and diastolic pressure

Answer 35

S: Pressure when ventricles are contracted (highest pressure) D: pressure when ventricles are relaxed (lowest pressure)

Question 36

What is a sphygmomanometer?

Answer 36

The equipment used to measure blood pressure average pressures are: Systolic - 100 - 140 (On top) Diastolic - 60 - 90 (On bottom

Question 37

What determines blood pressure?

Answer 37

Cardiac output: vol of blood leaving heart per minute Peripheral resistance friction on artery wall: pressure against blood vessel wall (effected by size of lumen and length of vessel)

Question 38

Define monosaccharide

Answer 38

Monomers e.g glucose, fructose, galactose. Containing hydrogen, oxygen and carbon. Sweet and soluble.

Question 39

Define disaccharide (include the bond and how it is formed)

Answer 39

Two monomers liked together with a 1-4 glycosidic bond formed by a condensation reaction. Sweet and soluble. Examples: maltose, lactose. Sucrose

Question 40

Define a Polysaccharide

Answer 40

Not sugars, insoluble, not sweet. Used to store energy rather than provide it. Examples: starch, cellulose, glycogen. Contain 1-4 and 1-6 glycosidic bonds. Therefore are chain molecules with branches coming off main chain. The end of the chain is known as a terminal end, more branches more ends.

Question 41

When connected by a 1-4 glycosidic bond what does fructose and glucose form?

Answer 41

Sucrose

Question 42

What two polysaccharides bond to make starch?

Answer 42

Amylase and amylopectin

Question 43

What is the basic structure of a triglyceride?

Answer 43

Three fatty acids bonded to a glycerol backbone by ester bonds. A phosphate group is also connected to the backbone, a variable group is then bonded to this phosphate group

Question 44

What is the effect of double bonds on fatty acids

Answer 44

The more double bonds the lower the intermolecular forces between bonds, this causes fatty acids to have a lower melting point

Question 45

What effects do carbon atoms have on melting point?

Answer 45

Carbon atoms increase the melting point of a molecule

Question 46

How is a triglyceride formed (molecularly)

Answer 46

``` CHv2OH (glycerol) + OH-C=O (fatty acid) -----> (condensation reaction) CHv2O-C=O (triglyceride) +Hv2O (water) ```

Question 47

What is a HDL and it's features

Answer 47

``` High density lipoprotein Unsaturated triglyceride More protien Less cholesterol Remove cholesterol from body to liver 'Good cholesterol' ```

Question 48

What is a LDL and it's features?

Answer 48

``` Low density lipoprotein Saturated triglyceride Less protein More cholesterol Cholesterol delivered to body cells, too high levels lead to atherscrolis ```

Question 49

What two groups can lipids be divided into?

Answer 49

Fats - solid at room temperature, saturated fatty acid Oils - liquid at room temperature, unsaturated fatty acid

Question 50

What is a unsaturated fatty acid?

Answer 50

Consist of one (monounsaturated) or more (Polyunsaturated) double bonds between carbon atoms in the hydrocarbon chain, double bonds links in structure so the molecule can not pack closely resulting in lower intermolecular forces making it a oil

Question 51

What is a saturated fatty acid?

Answer 51

No carbon to carbon double bonds in hydrocarbon chain, containing maximum number of hydrogen atoms, forming a long straight chain. They can closely pack forming tight intermolecular bonds making them a fat. Found in dairy and meat.

Question 52

How do you measure your BMI what is healthy and why is it bad about it?

Answer 52

Mass (kg) / height (m)^2 = BMI 20-25 is healthy for an adult It does not take fat/muscle ratio into account

Question 53

How do you measure your wait to hip ratio?

Answer 53

Waist/hip Men < 0.9 Woman < 0.85 Shows how body lays fat down

Question 54

How can high levels of LDL lead to CVD?s

Answer 54

Not all the cholesterol will be absorbed from blood, this is due to overloaded membrane receptors on cells, this excess will increase blood cholesterol levels, increasing chances of plaque to form and clogging up the lumen (atheromas) resulting in CVD

Question 55

What is an energy budget? How can it lead to obesity?

Answer 55

Energy budget is how much energy your body needs, for example the bigger you are more more exercise you do the bigger the budget, go under the budget you will lose weight, over causes you to gain weight.

Question 56

What is an antioxidant, and what does it do?

Answer 56

A molecule which inhibits the oxidisation of other molecules. Free radicals can be produced from oxidisation, they can cause chain relations which kill cells. Antioxidants terminate free radicals by oxidising themselves. Less free radicals stops cell damage lowering chances of CVD. Fruits like pineapple grapes berries are all antioxidants.

Question 57

How is cholesterol transported and why?

Answer 57

Mainly via LDLs as they are lipids and are not soluble they must bond to a protein to for a lipoprotein so they can be carried in the blood

Question 58

What are free radicals?

Answer 58

Molecules with unpaired electrons Found in fried foods, and made in the body Reactive molecules Oxidises LDL speeding up atherscorolis

Question 59

How do you reliably measure the vitamin C content of a substance

Answer 59

1. Pipette 1cm^3 of 1% DCPIP sol into a test tube 2. Drip 1% vit C sol into test tube shaking after each drop, when sol turns from blue to colourless measure exact amount used (repeat) 3. Repeat the step with juices in question (dilute juice if necessary) 4. The 1% vit C sol contains 10mg of vit C per 1cm^3, calc mass of vit C needed to decolorise the 1cm^3 of DCPIP sol. You can use this value to work out the bit C content of the other juices in mg cm^-3

Question 60

How to measure the effect of caffeine on the heart rate of a water flea (Daphina)

Answer 60

1. Take a few strands of cotton wool on a cavity slide, use a pipette to transfer a flea into the wool, make sure it is in distiller or pond water and do not use a cover slip, use a microscope to locate heart 2. Use a stopwatch to record bpm use pencil tapping method and partner time keeper (repeat) 3. Repeat procedure except remove the water and replace with various caffeine concentrations 4. Make a table and compare

Question 61

How does smoking tobacco increase chances of CHD

Answer 61

Carbon monoxide reduces RBCs ability to carry oxygen, meaning the heart will have to pump faster to provide the cells, increasing blood pressure. Nicotine increase rate of adrenaline production which constricts arteries and increases heart rate and blood pressure Tobacco smoke reduces HDLs in the body increasing cholesterol levels Chemicals found in smoke can damage the lining of arteries, triggering atherosclerosis

Question 62

What do ACE inhibitors do? And what are the side effects?

Answer 62

Lower blood pressure by reducing synthesis angiotensin II hormone which therefore reduces vasoconstriction Side effects: dry cough, dizziness, abnormal heart rhythms, and reduced kidney function.

Question 63

What do calcium channel blockers do? And what are the side effects?

Answer 63

Block calcium channels in muscle cells in the lining of arteries, stopping them from constricting, stopping vasoconstriction reducing blood pressure. Side effects can kill if you have weak heart. As well as dizziness, swollen ankles headaches, abnormal heart rhythms.

Question 64

What do Diuretics do? And what are the side effects?

Answer 64

Increase the volume of urine produced by kidneys, thus ridding the body of excess fluids and salt. Leading to a decrease in plasma in blood and cardiac output Side effects: dizziness, nausea, muscle cramps.

Question 65

What do Beta blockers do? And what are the side effects?

Answer 65

Same shape as adrenalin, they enter proton receptors in the heart preventing adrenalin from doing so so heart rate is not raised as much by lowering heart contractions. Usually taken with an ACE inhibitor

Question 66

What are the benefits/risks of taking statins, and what do they do?

Answer 66

Lower cholesterol by inhibiting an enzyme in LDL production, balance LDL and HDL by making more LDL receptors In the liver to remove LDL, reduce inflammation in artery lining. All of this reduces the risk of atherosclerosis. They quickly reduce risk of stroke or CHD. Normally no side effects however sometimes liver damage or fatal muscle inflammations

Question 67

What are the benefits/risks of taking anticoagulants, and what do they do?

Answer 67

They prevent blood clotting easily. Warfarin is an anticoagulant which interferes with prothrombin production, if low clots are harder to form. However too much and blood won't clot at all, which can lead to haemorrhaging

Question 68

What are the benefits/risks of taking platelet inhibitory drugs, and what do they do?

Answer 68

Make platelets less sticky, reducing clotting ability of blood, aspirin is a cheap commonly used PID. It can irritate the stomach lining which causes bleeding and can become serious.