Term
Is stimulated by nerves and is self-excitable (automaticity)
Contracts as a unit
Has a long (250 ms) absolute refractory period |
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Definition
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Term
| Use calcium influx (rather than sodium) for rising phase of the action potential (prolonging contracture) |
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Definition
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Term
| generates impulses about 75 times/minute |
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Definition
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Term
| node delays the impulse approximately 0.1 second |
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Definition
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Term
| Impulse passes from atria to ventricles via the |
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Definition
| atrioventricular bundle (bundle of His) |
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Term
| carry the impulse toward the apex of the heart |
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Definition
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Term
| carry the impulse to the heart apex and ventricular walls |
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Definition
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Term
| Heart is stimulated by the |
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Definition
| sympathetic cardioacceleratory center |
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Term
| Heart is inhibited by the |
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Definition
| parasympathetic cardioinhibitory center |
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Term
| corresponds to depolarization of SA node error Depolarisation of the atria!!!! |
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Definition
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Term
| corresponds to ventricular depolarization |
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Definition
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Term
| corresponds to ventricular repolarization |
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Definition
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Term
Heart sounds (lub-dup) are associated with closing of heart valves
First sound occurs as |
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Definition
| AV valves close and signifies beginning of systole |
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Term
Heart sounds (lub-dup) are associated with closing of heart valves
Second sound occurs when |
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Definition
| SL valves close at the beginning of ventricular diastole |
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Term
| contraction of heart muscle |
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Definition
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Term
| relaxation of heart muscle |
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Definition
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Term
Phases of the Cardiac Cycle
mid-to-late diastole |
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Definition
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Term
Phases of Cardiac Cycle:
AV valves are open, then |
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Definition
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Term
Phases of Cardiac Cycle:
Rising ventricular pressure results in.. |
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Definition
| in closing of AV valves(1) |
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Term
early diastole
Ventricles relax
Backflow of blood in aorta and pulmonary trunk closes semilunar valves |
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Definition
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Term
| brief rise in aortic pressure caused by backflow of blood rebounding off semilunar valves |
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Definition
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Term
| is the amount of blood pumped by each ventricle in one minute |
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Definition
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Term
| is the product of heart rate (HR) and stroke volume (SV) |
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Definition
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Term
| is the amount of blood pumped out by a ventricle with each beat (or stroke) |
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Definition
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Term
| is the difference between resting and maximal CO |
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Definition
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Term
| = end diastolic volume (EDV) minus end systolic volume (ESV) |
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Definition
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Term
| = amount of blood collected in a ventricle during diastole |
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Definition
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Term
| = amount of blood remaining in a ventricle after contraction |
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Definition
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Term
| amount ventricles are stretched by contained blood |
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Definition
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Term
| cardiac cell contractile force due to factors other than EDV |
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Definition
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Term
| back pressure exerted by blood in the large arteries leaving the heart |
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Definition
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Term
| is the critical factor controlling stroke volume |
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Definition
| Preload, or degree of stretch, of cardiac muscle cells before they contract |
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Term
| Agents/factors that decrease contractility include: |
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Definition
Increased extracellular K+
Calcium channel blockers |
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Term
| chronotropic factors increase heart rate |
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Definition
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Term
| chronotropic factors decrease heart rate |
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Definition
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Term
| is activated by stress, anxiety, excitement, or exercise |
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Definition
| Sympathetic nervous system (SNS) |
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Term
| is mediated by acetylcholine and opposes the SNS |
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Definition
| Parasympathetic nervous system (PNS) |
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Term
| dominates the autonomic stimulation, slowing heart rate and causing vagal tone |
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Definition
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Term
a sympathetic reflex initiated by increased blood in the atria
Stimulates baroreceptors in the atria, causing increased SNS stimulation |
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Definition
| Atrial (Bainbridge) reflex |
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Term
| Two Hormones that increase heart rate |
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Definition
| epinephrine and thyroxine |
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Term
| must be maintained for normal heart function |
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Definition
| Intra- and extracellular ion concentrations |
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Term
| Fetal heart structures that bypass pulmonary circulation |
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Definition
Foramen ovale
Ductus arteriosus |
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Term
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Definition
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Term
| connects pulmonary trunk and the aorta |
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Definition
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