Definitions Flashcards
(23 cards)
stroke volume
volume of blood ejected from each ventricle during systole
equation for Stroke volume
SV = end diastolic volume - end systolic volume
what is an equation for mean arterial pressure
MAP = diastolic pressure + 1/3 PP
definition of blood pressure
pressure of blood within and against arteries
what is an equation for BP
BP = CO X TPR (total peripheral resistance)
definition of cardiac output
volume of blood each ventricle pumps as a function of time
Cardiac output equation
CO = HR X SV
what is Ohms’ law is relation to vessel resistance
flow = pressure gradient/ resistance
what is Pouisselle’s law
flow = radius^4
what is an equation for pulse pressure (PP)
PP = systolic pressure - diastolic pressure
preload definition
load present before LV contraction has started; volume of blood at end of diastole
what does preload mean in a practical sense
pressure the LV must overcome to eject blood during contraction
what happens to afterload when arteries dilate
decrease
what is afterload
load after ventricles start to contract; vascular resistance
contractibility definition
force of contraction and change in fibre length
contractibility explained
when muscles contract myofibrils stay same length but sarcomere shorten - force of heart contraction that is independent of sarcomere length
elasticity definition
myocardial ability to recover to normal shape after systolic stress
compliance definition
how easily heart chamber expands when filled with blood volume
diastolic distensibility definition
pressure required to fill ventricles to the same diastolic volume
total peripheral resistance definition
total resistance to flow in systemic blood vessels from beginning of aorta to vena cava
what vessels provide the greatest resistance
arterioles
what does a pressure-volume loop reflect
contractility in end systolic pressure volume relationship
what reflects compliance
end diastolic pressure volume relationship
