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Physics 5.2
Stenosis
Term | Definition |
---|---|
Stenosis | a narrowing of the lumen of a vessel, produces disturbed flow, may produce turbulent flow |
flow speed | average flow speed in a stenosis must be greater than that proximal and distal to it, volumetric flow rate must be constant throughout the vessel |
volumetric flow rate | must be constant for three regions: proximal to stenosis at the stenosis distal to the stenosis equals: the average flow rate across the vessel X the cross sectional area of the vessel |
continuity rule | fluid is not created or destroyed as it flows through a vessel. therefore, it must have constant volume |
If stenosis has created an area that measures 1/2 that of the areas proximal and distal to it, the average flow speed WITHIN the stenosis MUST be 2 times that flow speed proximal and distal to the stenosis | |
If the stenosis has a diameter 1/2 that adjacent to it, the area at the stenosis is 1/4 that adjacent to it | |
the average flow speed must ; therefore quadruple at the stenosis | |
Poiseulilles law | description of how flow is related to pressure, radius, length, and viscosity |