Capillary Circulation Flashcards
Major functions of capillaries
nutrient/waste exchange
Capillary characteristics that facilitate exchange process
one cell thick walls, high surface area, slow flow velocity
What 3 factors are important in controlling the opening and closing of precapillary sphincters
decrease in PO2
decrease in PCO2
increase in adenosine
In general, production of ______ or _____ will result in opening precapillary sphincters
metabolites
vessel dilation
Why in increasing blood flow to a tissue it’s more advantageous to open additional capillaries rather than to force more blood through the same number of capillaries
because the more capillaires that are open, the higher the SA will be and the slower the blood velocity will be, which facilitates higher gas exchange
What are the 4 starling forces
capillary hydrostatic pressure
interstitual fluid oncotic pressure
capillary oncotic pressure
intersitial fluid hydrostatic pressure
capillary hydrostatic pressure
filtration
force of blood pressure that drives fluid out of capillaries and into tissues
interstitial fluid oncotic pressure
filtration
influence of proteins in the intersitiuam that tend to pull fluid out of capillaries
capillary oncotic pressure
reabsorption
similar to intersitial fluid oncotic pressure, but pull fluid into capillaries
interstitaial fluid hydrostatic pressure
reabsorption
similar to capillary oncotic pressure, but pushes fluid into capillaries
3 conditions that may lead to edema
elevated capillary BP, vasodilation, venous obstruction
How do elevated capillary BP, vasodilation, and venous obstruction result in edema
they result in a back up of blood/increased pressure in capillaries and prevent fluid reabsoprtion
functions of lymphatic capillaries
remove excess fluid of protein from intersitial space
