Term
| what is the function of arterial pressure? |
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Definition
| to ensure a constant supply of blood flow to the tissue despite the cyclic nature of the cardiac pump |
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Term
| what is systolic pressure? |
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Definition
| the intracardial pressure during or resulting from systolic contraction of a cardiac chamber - the highest arterial blood pressure reached during any given ventricular cycle |
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Term
| what is diastolic pressure? |
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Definition
| the intracardial pressure during or resulting from diastolic relaxation of a cardiac chamber - the lowest blood pressure reached during any given ventricular cycle |
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Term
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Definition
| the variation in blood pressure occuring in an artery during the cardiac cycle - the difference between the systolic (max) and diastolic (min) |
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Term
| what is the MABP? how is it calculated? |
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Definition
| the mean arterial blood pressure, or the pressure that exists in the artery if there was a steady flow from the ventricle. it is calculated by: diastolic pressure + 1/3 pulse pressure (diastolic pressure + (systolic – diastolic)/3) OR MABP = CO x R |
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Term
| where is the major drop in blood pressure during circulation? why? |
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Definition
| in the arteriole, where pulse pressure practically disappears and pressure drops from 80 to 30 mm Hg. this is due to 1) increase in cross sectional area and 2) increase in resistance (reduces pulse pressre/flux) |
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Term
| what is the function of the resistance-compliance filter? |
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Definition
| to maintain flow during diastole |
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Term
| how is TPR (total peripheral resistance) calculated? |
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Definition
| Q=pressure change/R becomes R=pressure change/Q, therefore TPR=(Pa-Pv)/Q which is usualy (102-2 mm Hg)/5 L/min = 20 mm Hg/L/min |
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Term
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Definition
| the amount of change/distention in a blood vessel due to pressure |
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Term
| how is arterial compliance calculated? |
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Definition
| Ca(arterial compliance) = change in volume/change in pressure |
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Term
| how does pressure change in more compliant arteries according to volume? |
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Definition
| the more compliant an artery, the less change in pressure for a given change in volume/SV (compliance = capacitance) |
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Term
| how does arterial compliance vary with age? |
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Definition
| as age increases, compliance occurs at lower and lower pressures |
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Term
| if a pump has low resistance and no compliance how will it function during systole and diastole? |
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Definition
systole: high pressure, total flow
diastole: no pressure, no flow |
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Term
| if a pump has low resistance and high compliance how will it function during systole and diastole? |
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Definition
systole: lower pressure, lower proportion of flow
diastole: higher pressure, low duration of flow |
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Term
| if a pump has good resistance and lower compliance how will it function during systole and diastole? |
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Definition
systole: intermediate pressure, lower proportion of flow
diastole: higher pressure, and flow maintained during diastole |
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Term
| how does some compliance (coupled with some resistance downstream) maintain flow? |
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Definition
| the aorta stretches w/potential energy during systole which is then released in diastole, maintaining flow |
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Term
| what is (pulse) pressure essentially determined by? |
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Definition
| how much volume is put into an arterial system and how quickly blood moves downstream (how quickly pressure then falls is determined by how quickly blood leaves the arterial system which is determined in turn by resistance downstream) |
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Term
| what are the 2 main determinants of MABP? |
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Definition
| mean arterial volume (how much blood is being added to the arterial system - determined by flow entering/leaving arterial system) and resistance downstream (how quickly blood flows away or out of the arterial system) |
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Term
| what is pulse pressure determined majorly by? |
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Definition
| compliance of the large arteries |
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Term
| what happens to pulse, systolic, and diastolic pressures if only stroke volume is increased, but not compliance? what would then happen if you dropped resistance a little? |
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Definition
| everything goes up, except systolic goes up a little more relative to diastolic. if resistance was dropped, diastolic would drop a little b/c outflow would be higher |
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Term
| what happens to pulse, systolic, and diastolic pressures if everything is kept the same, but resistance is increased? |
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Definition
| systolic and diastolic will increase, but pulse pressure remains the same (b/c systolic and diastolic increase at the same rate) |
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Term
| what happens to pulse, systolic, and diastolic pressures if compliance is decreased? |
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Definition
| this will increase pulse pressure by increasing systolic and decreasing diastolic pressure |
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Term
| what happens to pulse, systolic, and diastolic pressures if resistance is increased and compliance is decreased? |
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Definition
| systolic pressure will increase more than diastolic pressure and pulse pressure will increase (diastolic does increase some). this would likely happen as a result of increasing pressure to the point that compliance begins to decrease |
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