Blood Pressure Regulation and Hypertension Flashcards
rate of blood flow through the lungs and why
pulmonary blood flow constitutes the entire right ventricle. PBF is equal to the entire right ventricle volume of 5 L/min
what control mechanisms regulate blood flow to organ or tissue capillary beds
intrinsic control: within that tissue, sympathetic blood flow into caps, auto regulated
extrinsic blood flow SNS hormones
intrinsic- metabolic theory of auto regulation
as local tissue metabolism increases due to increased activity, local factors are produced by the tissue that dilates arterioles that perfuse the tissue resulting in increased blood flow to that tissue. it decreases resistance
O2 and nutrient supply to tissues increases as long as metabolism is increased
O2 decrease
cell metabolism
CO2 increase
cell metabolism
H increase pH decrease
cell metabolism
K+ increase
cell metabolism
adenosine
ATP breakdown
Histamine
mast cells
Nitric Oxide (NO2)
endothelium
Prostacyclin (PGI2)
endothelium
myogenic theory of autoregulation
myogenic- contraction originates in the muscle. true of cardiac and smooth muscle. Ca2+ stretch-activated smooth muscles open when pressure or force distends the cell membrane allowing the muscle to contract in response to stretch - increased perfusion pressure, increase VGCC, increased vasoconstriction, decreased flow - negative feedback
extrinsic blood flow (outside, not local) controls
ANS and Hormones/Neurohormones
which branch of ANS has control of blood vessel tone
sympathetic
alpha 1 receptor
NE, some EPI, constricts