6 Atheroma Flashcards
What is atherosclerosis?
The thickening and hardening of arterial walls as a consequence of atheroma.
What is atheroma?
The accumulation of intracellular and extracellular lipid in the intima and media of large and medium sized arteries.
What is arteriosclerosis?
The thickening of the walls of the arteries and arterioles usually as a result of hypertension and diabetes.
List and describe the 3 macroscopic features of atheroma
Fatty streak- lipid deposits in the intima causing raised areas
Simple plaque- individual, small deposits coalesce to form a raised plaque
Complicated plaque- thrombus forms in the vessel wall causing calcification of the plaque. This results in an aneurysm.
Name 3 common sites of atheroma
Aorta
Coronary arteries
Leg arteries
Cerebral arteries
Describe some of the early microscopic changes
Proliferation of smooth muscle cells
Accumulation of foam cells
Extracellular lipid increases
Describe some of the later microscopic changes of atheroma
Fibrosis
Necrosis
Increased inflammatory cells
Damage extends to the media
Name 4 clinical effects related to atheroma
Ischaemic heart disease
Cerebral ischaemia
Mesenteric ischaemia
Periferal vascular disease
List 4 predisposing factors to atheroma
Old age Male Hyperlipidaemia Smoking Hypertension Diabetes Alcohol Genetics
What is the ‘unifying hypothesis’ for atheroma?
Endothelial cells are injured
Causes platelet adhesion, smooth muscle cell proliferation
Increased uptake of LDLs
Matrix material and foam cells are produced
How do endothelial cells change in atheroma?
Altered permeability to lipoproteins
Secrete collagen
Stimulate the proliferation of smooth muscle cells
What is a smooth muscle cell’s function in atheroma?
Take up LDLs and other lipids to become foam cells. Synthesise collagen and proteoglycans
What inflammatory cells are involved in atheroma formation?
Neutrophils
Lymphocytes
Macrophages