2.7- pathology of cardiovascular disease

Question 1

what is atherosclerosis?

Answer 1

the formation of plaques called atheromas beneath the endothelium in the wall of an artery

Question 2

what do plaques initially consist of?

Answer 2

fatty material mainly made up of cholesterol

Question 3

what enlarges plaques over time?

Answer 3

the addition of fibrous material, calcium and more cholesterol

Question 4

3 things that happen as an atheroma grows

Answer 4

artery thickens

artery loses elasticity

arterys lumen reduced diameter

Question 5

what effect does a reduced diameter to an arterys lumen have and what does it lead to?

Answer 5

blood flow to the capillary bed served by that artery is restricted

leads to an increase in blood pressure

Question 6

when do symptoms of atherosclerosis arise?

Answer 6

remain absent until later in life

Question 7

4 conditions atherosclerosis can lead to

Answer 7

coronary heart disease

angina

strokes

heart attacks

Question 8

what is atherosclerosis the root cause of?

Answer 8

peripheral vascular disease

Question 9

what is blood clotting and what is its purpose?

Answer 9

protective mechanism triggered by damage to cells

to prevent loss of blood to a wound

Question 10

what happens when an atheroma ruptures and what does this lead to?

Answer 10

when an atheroma ruptures, it damages the endothelium

leads to release of blood clotting factors that activate cascade of reactions

Question 11

4 steps in blood clotting

Answer 11

enzyme prothrombin, which is always present in blood plasma but inactive, becomes converted to its active form thrombin

thrombin promotes conversion of molecules of fibrinogen (soluble protein) into threads of fibrin (insoluble protein)

fibrin threads become interwoven to form a meshwork that platelets stick to, forming a blood clot

wound is now sealed and a scaffold is produced upon which scar tissue can be formed

Question 12

example of a clotting factor

Answer 12

vitamin K

Question 13

2 problems that atheromas cause

Answer 13

make inside lining of an artery uneven

disturb smooth flow of blood

Question 14

what is thrombosis and how is it caused?

Answer 14

thrombosis is the formation of a blood clot in a vessel

caused when an atheroma is enlarged and bursts through the endothelium and damages it

Question 15

what effect does a thrombus have in an artery?

Answer 15

causes further blockage on top of the atheromas damage

Question 16

what does a thrombus become when it breaks lose?

Answer 16

embolus

Question 17

what does an embolus do and what is the effect?

Answer 17

embolus travels through the bloodstream until it blocks a blood vessel

blood flow is now severely restricted or completely blocked

Question 18

what effect does a thrombus have in a coronary artery?

Answer 18

may lead to a myocardial infarction (heart attack)

Question 19

what effect does a thrombus have an artery in the brain?

Answer 19

may lead to a stroke

Question 20

what happens in both heart attacks and strokes and what does it lead to?

Answer 20

cells are deprived of oxygen

leads to death of the tissues

Question 21

what are the peripheral arteries?

Answer 21

those other than;

aorta

coronary arteries

carotid arteries

Question 22

what happens to peripheral arteries affected by atherosclerosis?

Answer 22

their central cavity becomes narrower

Question 23

what does a narrow central cavity of a peripheral artery lead to?

Answer 23

leads to peripheral vascular disease which most commonly affects the leg arteries

Question 24

what is the reason for the pain experienced in peripheral vascular disease?

Answer 24

pain is experienced in leg muscles due to limited supply of oxygen

Question 25

what is **deep vein thrombosis**?

Answer 25

formation of a thrombus in a vein that is most commonly in the calf of the lower leg

Question 26

2 things that can happen to **extremities** affected by deep vein thrombosis

Answer 26

become painful and swell up veins close to skin surface become engorged with blood

Question 27

**where** does a thrombus go once it breaks free and what does it **do**?

Answer 27

when a thrombus breaks free, it becomes an embolus travels via the vena cava and heart chambers to the pulmonary artery here it may block a small arterial branch

Question 28

what is it **called** when an embolus blocks a small arterial branch?

Answer 28

a pulmonary embolism

Question 29

3 **symptoms** of a pulmonary embolism

Answer 29

chest pains breathing difficulties palpitations

Question 30

drugs taken in **usual** and **severe** pulmonary embolism cases

Answer 30

usual cases- anticoagulant drugs severe cases- thrombolytic drugs

Question 31

what does the term **lipid** refer to?

Answer 31

a group of compounds including simple lipids like fats and complex substances like steroids

Question 32

why is cholesterol an **important** lipid?

Answer 32

precursor for the synthesis of sex hormones testosterone, oestrogen and progesterone

Question 33

how is cholesterol **synthesised** and what is it a **basic component** of?

Answer 33

from saturated fats present in a normal balanced diet cell membrane

Question 34

**what** makes cholesterol and **where** does much of its production take place?

Answer 34

made by all cells 25% of total production takes place in the liver

Question 35

2 things that **make up** lipoproteins

Answer 35

lipid protein

Question 36

**function** of lipoproteins and where are they **present**

Answer 36

transport lipids from one part of the body to another blood plasma

Question 37

**where** is cholesterol transported and **how**?

Answer 37

transported to body cells by low-density lipoproteins produced by the liver

Question 38

what do most body cells **have** and **where**?

Answer 38

LDL receptors in the cell membrane

Question 39

what 2 things must happen for cells to **make use** of cholesterol?

Answer 39

molecule of LDL carrying cholesterol becomes attached to a receptor cell engulfs LDL cholesterol cholesterol released

Question 40

**5 steps in the cause of atherosclerosis**

Answer 40

once a body cell contains an adequate supply of cholesterol, a negative feedback system is triggered negative feedback system inhibits the synthesis of new LDL receptors now less of the LDL-cholesterol circulating in the bloodstream is absorbed by body cells some of the LDL-cholesterol is taken up by endothelial cells lining the inside of an artery cholesterol then deposited in an atheroma in the wall of an artery

Question 41

**when** is atherosclerosis likely to occur?

Answer 41

if a person eats a rich in saturated fat diet throughout their life

Question 42

**where** is excess cholesterol transported and **how**?

Answer 42

transported to the liver for elimination by high-density lipoproteins from body cells

Question 43

what is the **purpose** of the elimination of cholesterol in the liver?

Answer 43

prevents a high level of cholesterol accumulating in the bloodstream

Question 44

what does the **elimination** of cholesterol in the liver **depend** on?

Answer 44

a healthy balance between HDL-cholesterol molecules and LDL-cholesterol molecules

Question 45

what is the **average** percentage of blood cholesterol carried by HDL and LDL molecules?

Answer 45

HDL carries 20-30% LDL carries 60-70%

Question 46

2 things a **higher ratio** of HDL to LDL would **result** in

Answer 46

lower blood cholesterol reduced chance of atherosclerosis

Question 47

2 things seen in people who **exercise regularly**

Answer 47

concentration of HDL-cholesterol in the bloodstream is normally higher risk of CVD lower

Question 48

2 things that can **raise** HDL levels

Answer 48

replacement of saturated fat with unsaturated fat consumption of less total fat

Question 49

what can **lower** levels of cholesterol in the blood and **how**?

Answer 49

drugs called statins by inhibiting an enzyme essential for the synthesis of cholesterol by liver cells