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16 Cards in this Set
- Front
- Back
systole
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-active phase: ventricle contracts and blood is ejected into the circulation
- both AV valves are closed, preventing backflow into the atrium - both semilunar valves are open, allowing blood to leave the ventricle |
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diastole
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-passive phase: ventricles relax and fill with blood
- both semilunar valves closed, preventing backflow into the ventricles - both AV valves are open to allow blood to flow |
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atrial systole and diastole
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-systole and diastole usually refer to ventricles
- atria also have systole and diastole, but they are shorter and begin/ end before the related ventricular actions |
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cardiac cycle gen
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-sequence of mechanical events of a whole heartbeat
-diastole: atria and ventricles are relaxed and blood returning through the large veins flows through the open AV valves and into the ventricles - in order to complete filling the ventricles, you must contract atria |
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1. cardiac cycle
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1. atrial systole
2. ventricles still relaxed 3. atrial contraction completes filling of the ventricles |
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2. cardiac cycle
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1. ventricular systole begins
2. BP rises 3. all valves closed 4. isovolumetric contraction |
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3. cardiac cycle
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1. ventricular pressure higher than aortic/ MPA pressure
2. ejection |
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4. cardiac cycle
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1. ventricular diastole begins
2. BP falls 3. all valves closed 4. isovolumetric relaxation |
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5. cardiac cycle
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1. atrial pressure higher than ventricular pressure
2. AV valves open 3. passive filling |
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Pressure during diastole
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-ventricular P slightly lower than atrial
|
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Pressure during systole
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-during ventricular contraction, ventricular P rises steeply and exceeds the atrial P:
1. AV valves close |
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P and aortic valve
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1. closed: as long as ventricular P is lower than the aortic pressure, end of systole (=diastole)
2. open: when ventricular P exceed aortic P, blood ejected |
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P and AV valves
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-during decrease in ventricular P all valves are closed
...until it falls below atrial P and AV valves open |
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End diastolic P
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maximum volume of entire cardiac cycle
- because ventricle keeps filling up to the very end of diastole |
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End systolic V
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-lowest ventricular blood volume
- at end of systole |
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stroke volume
|
volume of blood ejected during systole
- difference between end-diastolic and end-systolic P |