L5.9 Atherosclerosis and vascular pathology 1 Flashcards
What is the intima lined with? What does it influence in terms of coagulation?
Lined by endothelium. Has coagulating promoting factors, and coagulating preventing factors.
The media is predominantly made of what? What is the difference in the media between muscular and elastic arteries?
Elastin. Muscular arteries have an internal and external elastic lamina. Elastic don’t.
Adventitia contains its own blood supply, what’s the name? Where is the adventitia thickest in?
Vasa vasorum. Thickest in veins as it has to withstand very high hydrostatic pressures.
What is the difference between arteriosclerosis, atherosclerosis and arteriolosclerosis?
When there is intimal damage and thickening, fibrosis occurs. This is arteriosclerosis, whereby there is loss of compliance.
If it’s specifically the arteries, then it’s atherosclerosis.
If it occurs in arterioles, whereby smooth muscles produce too much matrix, proteins from blood leak across damaged endothelium, then we have hyaline arteriolosclerosis.
What can arteriosclerosis lead to?
Ischaemia, micro-aneurysm, haemorrhage.
Explain in more detail what atherosclerosis is.
It is a build up of inflammatory, fibrotic and necrotic fatty material in arteries, aka fibroinflammatory lipid plaque.
What are the 4 possible steps in the formation of an atherosclerosis?
Fatty streaks, which is a build of of macrophage/smooth muscle cells ingesting LDL to become foam cells.
Damage, inflammation and cholesterol with fibrosis.
Stable plaque forms.
Unstable plaque rupture.
True or false? Fatty streaks are clinically insignificant. In fact they can occur in children from ethnic backgrounds where the history of atherosclerosis is low.
True.
What are some microscopic features of an atherosclerotic plaque?
Atheroma, foam cells, cholesterol clefts, calcifications, thinned media, mononuclear inflammatory cells.
In what two ways can calcification arise?
Dystrophic calcification appears in areas of cell degeneration such as in TB.
Metastatic calcification is when serum calcification and phosphate levels are too high. Therefore reaching precipitation threshold and fall out of solution.
What is an acute plaque event and what can it lead to?
Spontaneous rupture of plaque possibly leading to thrombosis, thromboembolism, atheroembolism.
What does an activated endothelium do?
Leaky, expresses adhesion molecules, produces cytokines becoming thrombotic.
Also takes up LDLs which are oxidised, becoming pro-inflammatory.
True or false? Monocytes and smooth muscle cells can become foam cells.
True. This results in a thicker fibrous cap.
What is an aneurysm?
Abnormal dilation of blood vessels due to weakness in media. True aneurysm is when blood extrudes from wall. False is a dissection.
There are fusiform (regular shaped balloon) or saccular aneurysms.
What is AAA?
Abdominal aortic aneurysm. Occurs when inflammatory environment weakens extracellular matrix (due to MMP). Risk of rupture if increases above 5cm.
