The vascular endothelium. Flashcards
Name some dilators of the endothelium.
NO, EDHF, Prostacyclins, Adenosine.
Name some constrictors of the endothelium.
Angiotensin 2, Thromboxane A2, Endothelin.
End product that produces Vasodilation.
cGMP. Produced through Guanyl cyclase acting on GTP.
Stuff that can cause endothelial dysfunction.
LDL, HTN, Diabetes, Smoking.
What can edothelial dysfunction lead to?
Vasoconstriction, Platelet adhesion, SMC migration and adhesion, Increased Lipid deposition.
Endothelial dysfunction is considered a good indicator of what medical condition?
Atherosclerosis.
Explaint the mechanism of endothelial dysfunction.
Vascular endothelial damage, Expression of adhesion molecules, Monocytes come, Migrate to media, Form foam cells, Fatty streaks appear to the naked eye, They accumilate to form plaque, Proliferation of smooth muscle, fibrous tissue, Plaques increase in size, Occlusion of artery.
Characteristics of A stable plaque.
Thick fibrous cap, preserved lumen.
Characteristic of an unstable plaque.
Thin fibrous cap.
What do you actually check for when assessing endothelial function?
Ability to release No in respone to physiologic or pharmacologic stimuli.
How to assess endothelial function in the heart?
Angiography, Coronary flow velocity reserve.
How do you assess endothelial function in the peripheral vascular bed?
Brachial Ultrasonography, Strain gauge Plethysmography.
What do you do in Brachial Ultrasosnography?
Measure the brachial artery diameter from high frequency ultrasound images. Reactive hyperemia is induced and flow mediated dilatation is measure.
What is reactive hyperemia.
A temporary increase in shear stress by increasing local blood flow.
Flow mediated dilatation.
An Endothelium-dependant process which reflects the relaxation of a conduit artery when exposed to increased flow. Normal - 5-15 % increase.
In a hose you open more of the tap and it gets larger.
