peripheral resistance control of Bp L12 Flashcards
(40 cards)
unit of cardiac output
Q
equation of cardiac output
Q= change in pressure/ resistance
Blood pressure cal=
cardiac output x resistance
blood flow is determined by
diameter of a vessel
resistance means
the impediment to blood flow along a vessel
what is short term control of blood pressure
neurological -ANS
where are sympathetic fibres to
all vessels in the body except capillaries
what do sympathetic fibres release
noradrenaline
what receptors does noradrenaline interact with
alpha receptors
what does alpha receptor stimulation cause
vasocontriction= increased peripheral resistance
what does venous constriction cause
increased venous return which increases cardiac output
what cardiac effects does the sympathetic nervous system have
increase HR
inotropic effect (pump stronger)
lusitropic effect
at rest what is there an underlying stimulation of
sympathetic NS
what receptors detect pressure
baroreceptors
where are baroreceptors
arch of aorta
carotid sinuses
where are the carotid sinuses
in internal carotid arterties
what do baroreceptors detect
stretch
what do baroreceptors effect
they cause increased/ decreased sympathetic outflow
chemically a decreased Bp causes
a decreased PaO2
what detects decreased PaO2
chemoreceptors
what is long term Bp control
hormonal
2 renal controls of Bp
pressure diuresis
renin angiotensin system (RAAS)
what is pressure diuresis
increased Bp–> increased blood flow to kidneys–> increased urination—> decreased BP
what does a increased salt and water intake mean
higher Bp