atherosclerosis

Question 1

atheroma

Answer 1

the accumulation of intracellular and extracellular lipid in the intima of large and medium sized arteries

Question 2

atherosclerosis

Answer 2

the thickening and hardening of arterial walls as a consequence of atheroma in large and medium sized arteries

Question 3

where does atherosclerosis occur

Answer 3

• aorta - especially abdominal
• coronary arteries
• carotid arteries
• cerebral arteries
• leg arteries

Question 4

structure of normal artery

Answer 4

• intima
• media
• adventitia

Question 5

medial layer of artery

Answer 5

contributes to most of the mechanical strength of an artery

Question 6

atheroma macroscopic features

Answer 6

• fatty streak
• simple (fibrous) plaque
• complicated plaque

Question 7

fatty streak

Answer 7

comprises a slightly elevated zone on the arterial wall caused by accumulation of a small number of lipid laden cells

Question 8

simple (fibrous) plaque

Answer 8

lipid accumulates both free and in cells, smooth muscle cells also migrate from the media, fibrosis develops around the lipid and forms a cap over the lesion

Question 9

complicated plaque

Answer 9

ulcers and fissures of the fibrous cap expose plaque contents resulting in thrombosis

Question 10

cause of atherosclerosis

Answer 10

• process not fully understood
• current hypothesis: response t injury
• initiated by endothelial dysfunction

Question 11

daily dietary cholesterol intake

Answer 11

300mg

Question 12

cholesterol

Answer 12

carried in the blood attached to proteins called lipoproteins
two main forms:
- LDL (low density lipoproteins)
- HDL (high density lipoprotein)

Question 13

LDL

Answer 13

is removed from the circulation by either LDL receptors or by scavengers cells such as monocytes or macrophages

Question 14

how does oxidised LDL form

Answer 14

occurs when the LDL particles react with free radicals

Question 15

risk factors that increase the levels of oxidised LDL

Answer 15

• consuming a diet that is high in trans fats
• smoking
• poorly controlled diabetes
• metabolic syndrome, which is often a precursor of diabetes
• exposure to toxins through pollution and preservatives
• stress

Question 16

hyperlipidemia

Answer 16

blood has too many lipids (or fats) such as cholesterol and triglycerides

Question 17

when LDL becomes oxidized

Answer 17

it goes directly into the endothelium and may alter the endothelial permeability

Question 18

atheroma prevention

Answer 18

• no smoking
• diet ~ reduce fat intake
• not too much alcohol
• regular exercise

Question 19

antiplatelet function in normal endothelium

Answer 19

• adenosine diphosphate ~ degrades ADP from platelets
• prostacyclin ~ produced by the enzyme cycloxygenase
• nitric oxide

Question 20

anticoagulant function in normal endothelium

Answer 20

• heparin-like-molecules ~ activate antithrombin III
• thrombomodulin (activates protein C)
• protein S

Question 21

antithrombotic function in normal endothelium

Answer 21

• fibrinolytic ~ prevents blood clots from growing
• t-PA

Question 22

procoagulant functions in damaged endothelium

Answer 22

• production of vWF (von Willebrand Factor~ protein that helps blood to clot)
• production of tissue factor
• binding of factors IXa and Xa