ARTHEROSCLEROSIS

Question 1

What is atherosclerosis? (1)

Answer 1

the progressive degeneration of artery walls.

Question 2

what are the steps of development? (3)

Answer 2

-endothelial damage
-raised blood pressure
-lesion formation and inflammatory response

Question 3

what are unhealthy arteries? (2)

Answer 3

unhealthy arteries, the walls have strands of yellow fat deposited under the endothelium.

Question 4

what are classified as death from atherosclerosis? (1)

Answer 4

premature deaths that occur before 75 years.

Question 5

how and what causes raised blood pressure? (2)

Answer 5

these deposits start to impede blood flow and contribute to raised blood pressure also thickening of artery walls leads to loss of elasticity.

Question 6

what are healthy arteries? (2)

Answer 6

healthy arteries have pale, smooth linings and the walls are elastic and flexible.

Question 7

what occurs if these deposits form in coronary arteries? (1)

Answer 7

the progressive reduction of blood flow impairs oxygenation of the cardiac muscle fibres leading to chest pains (angina).

Question 8

what and how are lesions formed? (3)

Answer 8

-when the smooth lining breaks down the circulatory blood is exposed to these fatty fibrous deposits.
-lesions are known as atheromatous plagues.
-further deposition occurs as cholesterol and triglycerides accumulate and smooth fibres muscle and collagen fibres proliferate in the plague.

Question 9

what and how is endothelial damage caused? (3)

Answer 9

-fat in unhealthy arteries builds up from certain lipoproteins and from cholesterol that may be circulating in the blood.
-this damage causes white blood cells (microphages) to include the fatty streaks where they begin to take up cholesterol from low density lipoproteins and develop fibrous connective tissue forming an atheroma.

Question 10

what and how an inflammatory response triggered? (2)

Answer 10

blood platelets tend to collect at the exposed, toughened surface and these platelets release factprs that trigger a defensive response (inflammation) which includes blood clotting.
-this is called thrombus until it breaks into the blood stream (called embolus)

Question 11

what major risk factors of coronary heart disease that cannot be controlled? (3)

Answer 11

-increasing age
-genetic factors
-some races

Question 12

what is a heart attack also called? (1)

Answer 12

myocardial infarction

Question 13

what major risk factors of coronary heart disease can we control or reduce? (4)

Answer 13

-hypertension
-high levels of cholestrol in blood
-smoking
-alcohol

Question 14

what can cause a blockage with an artery? (1)

Answer 14

a blockage can be caused by an embolus being swept into a small artery or arteriole that is narrower than the diameter of the clot causing this.

Question 15

what can result from a blockage in an artery? (1)

Answer 15

the blood supply to the tissue downstream of the block is deprived of oxygen. without oxygen the tissue dies.

Question 16

what occurs when an embolus blocks an artery in the brain? (1)

Answer 16

when an embolus blocks an artery in the brain, a stroke occurs.

Question 17

what happens when a blockage occurs in a artery that has been weakened by atherosclerosis? (2)

Answer 17

the remaining layers may be stretched and bulge under the pressure of the blood pulses. Ballooning of the wall like this is called an aneurysm which could burst at any time.

Question 18

what is meant by a heart attack? (1)

Answer 18

when a heart muscle dies by blockage causes the heart to cease being an effective pump.

Question 19

how do genetic factors effect the risk of CHD? (2)

Answer 19

the occurrences of heart attacks at relatively early age frequently runs in families suggesting genes can confer vulnerability to CHD. children of parents of heart diseases are distinctively more likely to develop the condition.

Question 20

what happens when a stroke occurs? (2)

Answer 20

neurones of the brain depend on a continuous supply of blood for oxygen and glucose. within a few minutes of blood supply being lost, the the neurones affected will die. Which cannot be replaced. this blockage results in loss of some body functions controlled by that region of the brain.

Question 21

what is defined as high blood pressure? (1)

Answer 21

systolic pressure greater than 140mmHg and diastolic pressure greater than 90mmHg.

Question 22

How does increasing age effect the risk of CHD? (2)

Answer 22

over 80% of people who die from CHD are 65 years or more though chances could be related to changes in lifestyle in early life.

Question 23

what is the result of hypertension? (3)

Answer 23

it increases the work load on the heart, causing it to enlarge and weaken with time. It also causes damage to blood vessels accelerating the onset of atherosclerosis. Brain and kidney can also be damaged. increases the risk of stroke making a brain haemorrhage more likely

Question 24

why are men much more likely to develop CHD than females? (1)

Answer 24

the possession of the Y chromosome predisposes a greater risk because of the production of the hormone oestrogen which inhibits the formation of atheroma and reduces the risk of CHD.

Question 25

what chemicals from smoking can cause damage to the cardiovascular system? (2)

Answer 25

nicotine and carbon monoxide in the smoke.

Question 26

what is considered normal blood pressure? (1)

Answer 26

120/80mmHg

Question 27

how does nicotine affect the cardiovascular system? (2)

Answer 27

the effects of nicotine are via its stimulation of adrenaline production. This hormone triggers an increase in heart rate and causes arteries to contract (vasoconstriction) results in raised blood pressure.

Question 28

how can hypertension be treated? (1)

Answer 28

hypertensions a condition that, once detected can be regularly monitored can be successfully treated with drugs.

Question 29

why are lipids transported around the body? (2)

Answer 29

both in their role as respiratory substrates for the transfer of energy and as cholesterol for use in the production of steroid hormones and the maintence and repair of cell membranes.

Question 30

how does carbon monoxide affect the cardiovascular system? (1)

Answer 30

carbon monoxide combines irreversibly with haemoglobin in red cells, reducing the ability of blood to transport oxygen to all respiring cells (cardiac fibres)

Question 31

why are lipids held in association with proteins? (1)

Answer 31

because they are insoluble in water.

Question 32

what are LDLs known as? (1)

Answer 32

‘bad cholesterol’ when combined with saturated fats.

Question 33

what are the two types of lipoproteins? (2)

Answer 33

low density lipoproteins
high density lipoproteins

Question 34

what are HDLs known as? (1)

Answer 34

‘good cholesterol’ when combined with unsaturated fats.

Question 35

where is this excess in LDLs stored? (3)

Answer 35

the excess is then deposited under the endothelium of artery walls initiating or enhancing plague formations, however monounsaturated fats help remove the circulating LDLs and polyunsaturated fats are even more beneficial for they further increase the efficiency of the receptor sites at removing the ‘bad cholesterol’ from the blood.

Question 36

what can an excess of LDLs cause? (2)

Answer 36

an excess of these in the bloodstream has been shown to block up the many receptor points in the cell membranes of cells that metabolise or store lipids leaving even higher quantities of LDLs circulating in the blood plasma.

Question 37

why is it important to show caution when avoiding a diet rich in saturated fats and cholesterol? (1)

Answer 37

the lipids is an essential body metabolite that is manufactured in the liver in the absence of absorbed dietary cholesterol.

Question 38

how does alcohol increase the risk of CHD? (2)

Answer 38

an excessive intake of alcohol levels leads to raised blood pressure, damaged heart muscle and irregular heart beats. it also causes raised LDL levels in the blood and is associated with certain cancers.

Question 39

what is the formula to calculate BMI? (1)

Answer 39

body mass in kg / (height in m) 2

Question 40

how does physical inactivity, obesity and being overweight increase the risk of CHD? (1)

Answer 40

moderate activity helps prevent heart and blood vessel disorders to do this we use BMI.