Atheroma/Atehrosclerosis Flashcards
What is aneurysm formation?
dilation of an artery due to a weakness in its wall
What is arterial dissection?
splitting within the media by blood - false lumen fills with blood, sudden collapse and high mortality
What happens during the migration of smooth muscle cells from media to intima?
smooth muscle cells trapped - take up cholesterol - produce extracellular matrix - fibrofatty plaque formation
What happens during accumulation of lipids and macrophages?
macrophages take up cholesterol. LDL deposited
What is the aetiology of atheroma?
cigarette smoking - endothelial injury, hypertension - haemodynamic injury, hyperlipidaemia, diabetes - increased cholesterol levels abnormal cross-linking in vessel walls which decreases elasticity and traps cholesterol, increasing age, male, post-menopausal females, genetics
What are the complications of an aneurysm?
rupture - >6cm diameter, thrombosis, embolism, pressure erosion of adjacent structures, infection
What is the pathogenesis of atheroma?
primary endothelial injury, accumulation of lipids and macrophages, migration of smooth muscle from media to intima, increases in size
What is arterial dissection associated with?
atheroma, hypertension, trauma, coarctation, Marfan’s, pregnancy
What are the complications of atheroma?
arterial stenosis, aneurysm formation, arterial dissection
What is arterial stenosis?
reduced lumen and elasticity - reduced flow - tissue ischaemia
What happens after primary endothelial injury?
increased permeability - increased white cell adhesion - increased VCAM-1 etc. - monocytes attach and migrate through wall
What is ischaemia?
insufficient blood supply
What is moderate stenosis?
Between 50-70% stenosis
What is severe stenosis?
> 70% stenosis
