atherosclerosis Flashcards
Define ateriosclerosis
Hard arteries
Define atherosclerosis
A type of arteriosclerosis with fatty build-up
Define fibroatheroma
A type of arteriosclerosis with fatty and fibrous build up
atherothrombosis
Atherosclerosis with thrombosis
How do endothelial cells normally prevent atherosclerosis?
How are they stimulated to respond normally?
- maintain an antithrombotic surface
- low propensity to synthesize ECM
- produce antioxidants and antithrombotics
- produce NO, keep SMCs relaxed
- normal laminar flow (shear stress)
How does atherosclerosis start?
- endothelial injury. Can be chemical irritants (tobacco smoke, lipids, glucose) or physical (HTN, branch points
What sort of things do abnormal (dysfunctional) epithelial cells do ?
- altered permeability
- prothrombotic
- pro-leukocyte adhesion
- poor vasodilation
- secretion of growth factors
- increased oxidative state
What are the steps in atherogenesis?
1) endothelial injury
3) LDL and leukocytes get into the subendothelial space
4) T-cells produce cytokines
5) Macrophages eat LDL and become foam cells, die
At the same time, smooth muscles are transformed into spastic, migratory cells by the inflammation. Lots of ECM is produced
Differentiate between compensatory remodelling and non-compensatory
Compensatory grows out so the lumen does get occluded too much
Non-compensatory grows into the lumen
Contribution of platelets in atherogenesis
- they are activated by injured endothelium, and may clot causing further irritation of endothelium.
Characteristics of stable and vulnerable plaques
Stable: thick fibrous cap, many SMCs and collagen, small lipid core, few foam cells and little inflammation, lots of calcium
Vulnerable plaques are the opposite of this…
How does smoking contribute to atherosclerosis?
Smoking is associated with more oxidized LDL, endothelial dysfunction, increased platelet reactivity
How does diabetes contribute to atherosclerosis?
Glycated LDL leads to endothelial dysfunction
How does hypertension contribute to atherosclerosis?
- barotrauma
- AngII promotes oxidation
Define: atheroma
The fatty material that forms part of an atherosclerotic plaque
