Module 9 ML- 4 Part 2 Flashcards
Active Hyperemia
Active: more metabolic activity
Hyperemia: increase blood flow
What happens during active hyperemia
increased metabolic activity of organ
-decrease O2 and metabolites in organ ISF
-arteriolar dilation in organ
- increased blood flow to organ
What happens to the organ when there is increased metabolic activity
an increase in CO2, decrease in O2, and pH which causes dilation and that increased radius and flow
What happens during flow autoregulation
-increased arterial pressure in organ
-increased blood flow to organ
-increased O2, decreased metabolites and increased vessel wall stretch in organ
-arteriolar constriction in organ
-restoration of blood flow toward normal in organ
With higher pressure what happens
higher pressure, higher flow and bigger radius
What is the danger of higher pressure and bigger flow
it could tear apart capillary beds so the smooth muscle of arteriole detects stretch and contractions and vasoconstriciton occures to decrease flow while oressure is still high
What are the steps of the myogenic response during flow autoregulation
- MABP goes up, arterial bp and stretch goes up
- increase of activation of stretch sensitive calcium channels
-influx of calcium from ECF into smooth muscle cells
-contraction of smooth muscle cells
Reactive hyperemia
rebound blood flow and increased blood flow
What changes in the local factors cause vasodilatio
decrease O2 and pH and increased CO2, ECF potassium and increase adenosine
What do local controls do
match blood flow to demandW
What do extrinsic controls do
protect map
Norepi stimulates what
alpha 1 receptors which cause vasoconstriction
Epi stimulates what
beta 2 which cause vasodilation
What happens if you inject a higher dose of epi
can cause constriction
True or False; only symp innervantion of vasculature
true
