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11 Cards in this Set
- Front
- Back
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Atherosclerosis |
Specific form of arteriosclerosis affecting primarily the intima of large and medium sized muscular arteries and is characterized by fibrofatty plaques or atheromas |
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Atheroma |
Athero: soft lipid rich material in the center of atheroma Sclerosis: referring to CT in the plaques |
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Major Risk Factors |
1.) Dyslipidaemias 2.) Hypertension 3.) Smoking due to reduced level of HDL, deranged coagulation system & accumulation of carbon monoxide 4.) Diabetes Mellitus 5.) Age Sex: women less affected due to oestrogen & HDLs which are antiatherogenic 6.) Sex: women less affected due to oestrogen & HDLs which are antiatherogenic 7.) Genetic Factors
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Minor Risk Factors |
1.) Developed countries 2.) Obesity 3.) Use of exogenous hormones 4.) Physical inactivity 5.) Stressful lifestyle 6.) Patients with homocystinuria 7.) Elevated C reactive protein |
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2 major risk factors which act together to produce endothelial injury: |
1.) Haemodynamic stress from hypertension 2.) Chronic Dyslipidaemias |
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IL-1 and TNF-a lead to local synthesis of growth factors each having a role in plaque evolution: |
1.) PDGF and FGF: stimulate proliferation and migration of smooth muscle cells from media to intima 2.) TGF-b and IFN: regulate synthesis of collagen by smooth muscle cells NO and endothelin released from endothelial cells also also facilitate smooth muscle proliferation |
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Role of blood monocytes in plaque formation: |
Plasma LDL upon entering intima undergoes oxidation Oxidized LDL formed in the intima: -for monocytes, oxidized LDL attracts, proliferate, immobikize and activates the monocytes and oxidized LDL is taken up by scavenger receptors on monocyte to transform to LIPID LADEN FOAM CELL -oxidized LDL is cytotoxic and death of foam cell by apoptosis releases lipid to form lipid core of plaque |
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Morphological Features of Atherosclerosis |
Fatty streaks: flat or elevated and yellow Microscopically- foam cells, lipid containing elongated smooth muscle cells and lymphoid cells Gelatinous Lesion Atheromatous Plaque: fully developed atherosclerotic lesion |
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microscopic Morphology of Atheromatous Plaque |
1.) Superficial luminal part of the fibrous capbis covered by endothelium, smooth muscle cells, dense CT and ECM containing proteoglycan and collagen 2.) Cellular area under cap contains microphages, foam cells, lymphocytes and smooth muscle cells 3.) Deep central soft core: extracellular lipid material, cholesterol cleft, fibrin and foam cells |
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Complicated Plaques |
Pathologic changes that occur in fully developed atheromatous plaques |
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Changes that occur in complicated plaques: |
Calcification Ulceration Thrombosia Haemorrhage Aneurysmal Dilatation |
