Term
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Definition
| starts when the AV valves close and the pressure within the ventricles begins to rise as the cardiac muscle fibers are depolarized and then contract |
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Term
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Definition
| starts with ventricular muscle repolarization, leading to a drop in ventricular pressure, and filling of the ventricle |
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Term
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Definition
| very brief; thus, ventricular filling is largely passive |
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Term
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Definition
| (sv)(hr) stroke volume times heart rate |
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Term
| Determinants of Stroke Volume (3) |
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Definition
preload end diastolic volume
afterload aortic blood pressure
contractility |
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Term
| Afterload- Ventricles can not eject blood into the aorta or pulmonary artery until |
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Definition
| the pressure in the ventricle exceeds the pressure in the vessel |
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Term
| afterload- increase in pressure will |
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Definition
| have a major impact on the work of the heart & on stroke volume |
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Term
| stroke volume can not increase unless |
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Definition
| rate of cardiac filling also increases |
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Term
preload goes _________ heart
afterload goes _____ heart |
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Definition
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Term
active contractility
passive contractility |
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Definition
stimulation of sympathetic nerves in heart wall
result of changing the length of cardiac muscle fibers(frank starling mechanism) |
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Term
| Frank Starling Mechanism refers to |
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Definition
| increase in stroke volume and increase in preload |
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Term
| epinephrine and norepinephrine lead to |
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Definition
| increase rate of pacemaker activity and increased force of cardiac muscle contraction |
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Term
| Action potentials invade the __ __________; _______ is released from sarcoplasmic reticulum |
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Definition
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Term
| The norepinephrine also increases the _______________ of the cardiac muscle fibers to _________ |
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Definition
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Term
| In active contractility, the number of actin myosin crossbridge interactions _________ due to the permeability of calcium to cardiac muscle fibers |
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Definition
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