Atherosclerosis Flashcards
What is atheroma?
Focal accumulation of lipid in the intima of arteries
What is atherosclerosis?
Atheroma causing hardening and narrowing of arteries
Atherosclerosis: narrowing of arteries due to thickening of endothelium by _______ and ________ _______ (atherosclerotic plaques)
Lipids, fibrous tissue
What are the three main sites of atherosclerosis and what CVS disease is associated with each site?
Coronary arteries - ischaemic heart disease
Carotids and cerebral circulation - cerebrovascular disease
Legs - peripheral vascular disease
Atheroma lesions in the arterial walls will become _______ and often will _______. This process involves mineralisation and deposition of calcium salts which will cause the arteries to physically harden.
Fibrotic, calcify.
What are the risk factors of atherosclerosis? (11 points)
- Hypertension
- Hyperlipidaemia/raised LDL-cholesterol blood levels
- Diabetes mellitus
- Smoking
- Family history
- Aging
- Males
- Post-menopausal
- Obesity
- Lack of exercise
- Low socio-economic status
What are the three development stages of atherosclerosis?
- Fatty streak
- Fibrolipid plaque
- Complicated lesion
What happens during the formation of a fatty streak? (5 points)
- Endothelial damage
- Permeability (lipids can enter into the intima of the artery)
- Monocyte adhesion (to the endothelium)
- Entry of LDLs (together with monocytes into intima of artery)
- Foamy macrophages (macrophages that have taken up LDLs but can’t digest the fat so are filled up with fatty droplets and sit in the intima)
Monocytes adhere to the damaged endothelium and then migrate through the endothelium into the intima by a process called __________ which describes movement of a WBC through the vessel wall.
Diapedesis
Monocytes are precursor cells of ___________. Their differentiation is stimulated by ____________.
Macrophages, cytokines
Apart from the monocytes, we also find lymphocytes in the fatty streak, particularly ___ _________ which secrete cytokines that stimulate the monocytes to differentiate into ____________. At the same time, the increased permeability of the endothelium allows LDLs to be taken up by the macrophages that then expands into ______ cells, which are essentially a large cytoplasmic bag filled with _______ globules and the nucleus is compressed to one side of the cell so it can hardly be seen.
T lymphocytes, macrophages, foam, lipid
How some fatty streaks evolve into __________ plaques:
○ T cells release ___________ which stimulate the smooth muscle cells of the media which then come through the internal elastic lamina and migrate into the plaque
○ To a certain extent smooth muscle cells are also ____________ - they will take up some of the LDL and make the plaque more prominent and elevated
Fibrolipid, cytokines, phagocytic
How does fibrolipid plaque form? (5 points)
- Smooth muscle cells
- Migration
- Proliferation
- Lipid uptake
- Production of collagen
How does complicated lesion form? (8 points)
- Occlusion (of vessel by plaque)
- Ulceration (of fibrolipid plaque)
- Thrombus formation
- Haemorrhage into plaques
- Plaque fissuring & rupture
- Embolism
- Calcification
- Aneurysm formation
If rupture doesn’t heal and there’s complete blockage of the artery, it can lead to ______ _________ ________.
Acute myocardial infarction
infarct = stuffed with blood
