8 - Atherosclerosis

Question 1

Arteriosclerosis

Answer 1

Thickening of arterial wall which then loses elasticity

Question 2

3 steps in development of atherosclerosis

Answer 2

1 - Endothelial damage
2 - Uptake of modified LDL particles, adhesion and infiltration of macrophages
3 - Smooth muscle proliferation and formation of fibrous cap

Question 3

4 endothelial functions

Answer 3

Vasomotor tone
Thrombosis
Inflammatory factors
Cellular adhesion molecules

Question 4

Causes of endothelial damage

Answer 4

Shear stress
toxic damage
high LDL levels
Viral/bacteria

Question 5

VLDL

Answer 5

Very low density lipoprotein
Liver to cells
B100, A,C,E

Question 6

Chylomicron

Answer 6

Largest lipoprotein

B48, A,C,E

Question 7

IDL

Answer 7

Intermediate density lipoprotein
Breakdown product of VLDL
B100, E

Question 8

LDL

Answer 8

Low density lipoprotein
Fat from cell to blood vessel
B100

Question 9

HDL

Answer 9

High density lipoprotein
Removes fat from blood vessel to liver
A1, AII, C,E

Question 10

What facilitates and decreases oxidisation of LDLs

Answer 10

Reactive oxygen species in pollutants/nicotine facilitate

Antioxidants in fruit and veg decrease

Question 11

What facilitates glycation

Answer 11

High glucose levels

glycated LDL more likely to be oxidised

Question 12

How are monocytes transformed to fatty streaks

Answer 12

Monocytes cross the endothelium and are transformed into macrophages
They accumulate large droplets of lipid to become foam cells
this then becomes a fatty streak

Question 13

What receptor is modified LDL uptaken by

Answer 13

Scavenger receptor

Question 14

Where does smooth muscle proliferation take place

Answer 14

Intima

Question 15

What is the role of PDGF

Answer 15

Growth factor released by endothelial cells and macrophages
Causes proliferation of SMC
Also chemoattractant

Question 16

Stable plaque

Answer 16

Reduces blood flow, slow growing, increasing plaque volume causes stenosis of lumen and limits flow (stable angina) no thrombus

Question 17

Unstable plaque

Answer 17

Unstable fibrous plaque, can rupture and haemorrhage - release of platelet TF - clotting cascade- collagen exposed causing platelet aggregation
Forms a thrombus which may cause a Mi

Question 18

Desirable total cholesterol

Answer 18

Under 200mg/dl

Question 19

Desirable LDL

Answer 19

Under 130 mg/dl

Question 20

Desirable HDL

Answer 20

over 40mg/dl

Question 21

Desirable triglycerides

Answer 21

10-190mg/dl

Question 22

Atherosclerosis risk factors

Answer 22

Age, Sex, family history
Smoking, hypertension, diabetes, physical activity
Homocystinaemia, infection

Question 23

What do statins do

Answer 23

Inhibit HMG CoA to decrease cholesterol in liver cells, increase LDL receptors and decrease plasma cholesterol

Question 24

Complications of atherosclerosis

Answer 24

Coronary Artery Disease
Stroke
Aneurysm
Renal artery stenosis

Question 25

What do LDL receptors recognise

Answer 25

Apoplipoprotein B100

Question 26

What usually occurs in LDL uptake

Answer 26

Negative feedback - accumulation of LDL, decrease in LDL receptors and decrease in LDL uptake

Question 27

What occurs in atherosclerosis in LDL uptake

Answer 27

Modified LDL are not recognised by LDL-receptor modified LDL uptake by scavenger receptor UNLIMITED UPTAKE LDL accumulates in large droplets (foam cells)

Question 28

What causes fatty streak to turn into a mature plaque

Answer 28

Endothelial cells + macrophages release growth factors such as PDGF Proliferation of SMCs in intima + collagen production Breakdown of internal elastic lamina SMC --> foam cells Collagen forms fibrous cap

Question 29

What is the polypill

Answer 29

Statin Folic acid 3bp lowering drugs to reduce LDL + bp