Term
| 5 phases of the cardiac cycle |
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Definition
1. the heart at rest: atrial & ventricular diastole
2. completion of ventricular filling: atrial systole
3. early ventricular contraction & the first heart sound
4. the heart pumps: ventricular ejection
5. ventricular relaxation & the second heart sound |
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Term
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Definition
| created by vibrations following closure of the AV valves; the "lub" of "lub-dup" |
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Term
| Is the volume of blood in the ventricle changing during the isovolumic ventricular contraction phase? |
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Definition
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Term
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Definition
| created by the vibrations created by semilunar valve closure; the "dup" of "lub-dup" |
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Term
| Is the volume of blood in the ventricles changing during the isovolumic ventricular relaxation period? |
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Definition
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Term
| end-diastolic volume (EDV) |
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Definition
| the volume of blood when maximum filling occurs at the end of ventricular relaxation |
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Term
| end-systolic volume (ESV) |
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Definition
| the volume of blood left in the ventricle at the end of contraction |
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Term
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Definition
| the amount of blood pumped by one ventricle during a contraction |
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Term
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Definition
| the volume of blood pumped by one ventricle in a given period of time |
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Term
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Definition
| the intrinsic ability of a cardiac muscle fiber to contract at any given fiber length & is a function of Ca2+ interaction with the contractile filaments |
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Term
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Definition
| the degree of myocardial stretch before contraction begins; this stretch represent the load placed on cardiac muscles before they contract |
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Term
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Definition
| used to determine end-diastolic volume; the amount of blood that enters the heart from the venous circulation |
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Term
| 3 factors that affect venous return |
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Definition
1. contraction or compression of veins returning blood to the heart
2. pressure changes in the abdomen & thorax during breathing
3. sympathetic innervation of the veins |
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Term
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Definition
| skeletal muscle contractions that squeeze veins, compressing them & pushing blood toward the heart |
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Term
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Definition
| created by movement of the thorax during inspiration |
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Term
| What is the difference between an inotropic agent & an inotropic effect? |
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Definition
agent: any chemical that affects contractility
effect: the influence of the agent |
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Term
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Definition
| a regulatory protein that allows catecholamines to increase Ca2+ storage |
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Term
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Definition
| the combined load of blood in the ventricle & arterial resistance during ventricular contraction |
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Term
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Definition
| the percentage of EDV ejected with one contraction; a common functional index |
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