Vascular Endothelium Flashcards
role of vascular endothelium in blood vessel and tissue health?
provides angiocrine factors
- maintenance of tissue homeostasis and organ regeneration
what can dysfunctional endothelium cause?
Ischaemia Infarct Chronic Inflammatory diseases cancer diabetes
vascular and endothelial heterogeneity why is this a thing?
allows for different tissues to serve their different purposes
BBB : tight non fenestrated
kidneys, liver which require exchange and filter fluid sin blood have discontinous and fenestrated
role of endothelium
vascular tone regulation permeability inflammation haemostasis thrombosis angiogenesis
adhesion molecules{monocytes}
ICAMs
VCAM
Selectins
inflammatory mediators
leukotrienes
interleukin 1,6,8
MHC II
endothelium is activated under what conditions?
when under stress / triggers virus smoking mechanical stress inflammation High BP high glucose
pathogenesis of atherosclerosis
endothelial dysfunction
endothelial dysfunction due to activated endothelial
leukocyte adhesion and migration (ICAM,VCAM)
> into sub endothelial space
macrophage accumulation in sub endothelial space, where they break down lipids
what does endothelial dysfunction mean?
increased permeability to lipoproteins
mediated by NO, prostacyclin etc
mechanisms of endothelial dysfunction - in atherosclerosis
leukocyte recruitment
permeability
shear stress
angiogenesis
mechanism 1 leukocyte recruitment
leukocyte get stuck in sub endothelial space of large arteries
monocytes > differentiate into macrophages > foam cells
mechanism 2 permeability
Increased permeability
leakage of plasma proteins > subendothelial space
mechanism 3 shear test
Shear test:
where blood flow is laminar its more stable as shear stress is HIGH and directional laminar flow promotes NO production = antithrombotic properties
blood flow turbulent at bifurcations, more likely for endothelium to be disrupted as it promotes
thrombosis, inflammation, leukocyte adhesion
SMC proliferation
which ion has proven to have several protective properties?
NO reduces oxidation of LDL reduces platelet activation inhibits monocytes adhesion reduces releases superoxide radicals vasodilatory effects
what are some essential function of angiogenesis
menstrual cycle
embryonic development
wound healing
