B3W4 Flashcards
What are the local regulators of peripheral resistance that contribute to blood pressure?
nitric oxide, endothelin, hydrogen (that decreases pressure), oxygen, adenosine, prostaglandins
What are the two main characterizing topics of blood pressure
cardiac output and TPR
Arteries are ….. vessels
elastic
veins are …. vessels
compliant
arterioles are … vessels
highly resistant
capillaries are …. vessels
filtration vessels
explain compliance v elastance
higher elastance = more bounce back
high compliance = easier to stretch
Compare the veins and aorta’s wall thickness and elastic ability
veins = less elastic, thinner walls
aorta = more elastic, thicker walls
Flow, velocity and area relationship
flow = velocity * cross sectional area
a high p-MLC : total t-MLC
high contraction, high force, more XB
low p-MLC : total t-MLC
low concentration of XB, decreased force
how do cAMP and cGMP affect VSMC
-cAMP upregulates PKA for vasodilation
-cGMP upregulates PKG for vasodilation
An increase in transmural pressure causes…
constriction
What are the metabolites and their effects that communicate between endothelial cell and VSMC
endothelial - contraction
NO - dilation
adenosine - dilation
EDHF- dilation
prostaglandins - dilation
What are long term affects that could lead to chronic NOS production
cytokines response to infection, hypoxia, shear stress
Endothelium senses increases in …… pressure gradients leading to sheer stress
longitudal
Compare long and short term responses to flow (blue figure)
short term: sheer stress response allows for Gq pathway to induce NO production to trigger dilation
long term: gene transcriptiono
What does PDE do
breaks down cGMP to aid in vasoconstriction
What do PDE inhibitors do
inhibit phosphodiesterase to stop the break down of cGMP to keep dilation
what is a common PDE inhibitor
viagra
Why would you not want to have a pt with PDE inhibitors take nitorglycerin
they are both vasodilators that have synergistic effects which would lead to excessive dilation
how would you dx an endothelial dysfunction
FMD
what are the main concerns when looking at endothelial dysfunction
there will be abnormal vasoconstriction due to
-decreased NO production
-decreased NO avaliability
-Oxidative stress leads to NO inactivation
What are the circulations that are autoregulated?
cerebral, coronary and renal
