Term
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Definition
| Maps electricity of the heart. |
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Term
| What are the three main types of cardiac arrhythmias? |
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Definition
| Atrial flutter, premature ventricular contractions and Ventricular fibrillation |
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Term
| What is an Atrial flutter? |
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Definition
| Ectopic foci in atria, beats 200-400 times/min. |
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Term
| what is a premature ventricular contraction? |
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Definition
| Early firing of ectopic focus. |
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Term
| What are some causes of PVCs? |
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Definition
| stimulants, emotional stress, lack of sleep. |
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Term
| Can PVCs sometimes be serious? |
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Definition
|
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Term
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Definition
| Electrical signals arriving at different regions of myocardium at very different times. |
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Term
| Out of atrial flutters, PVCs and Vfib, which one is the most serious and life threatening? |
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Definition
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Term
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Definition
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Term
| Why is the SA node the "pacemaker" of the heart? |
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Definition
| It spontaneously depolarizes FASTER |
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Term
| spontaneous depolarization is also known as...? |
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Definition
|
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Term
| What causes spontaneous depolarization in the SA node? |
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Definition
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Term
| What makes the pacemaker potential different from other membrane potentials? |
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Definition
| Since Na causes the spontaneous depolarization, the cells DO NOT need innervation. The cells are depolarizing themselves. |
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Term
| What lets the Na into the cells? |
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Definition
|
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Term
| What can abnormal pacemakers do? |
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Definition
| cause bradycardia and tachycardia |
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Term
| Step one in cardiac impulse conduction is...? |
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Definition
| SA node spontaneous depolarization. |
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Term
| Step two in cardiac impulse conduction...? |
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Definition
| Stimulus reaches AV node. |
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Term
| Step three in cardiac impulse conduction...? |
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Definition
| Delay at AV node while atria contract. |
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Term
| Step four in cardiac impulse conduction...? |
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Definition
| Travels down AV bundles branches to purkinje fibers and to papillary muscles. |
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Term
| Step five in cardiac impulse conduction...? |
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Definition
| Impulse distributed by purkinje fibers and sent through ventricular myocardium. |
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Term
| During what step of the impulse conduction through the heart does atrial contraction end and ventricular contraction begin? |
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Definition
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Term
| What does a cardiac cycle consist of? |
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Definition
| one complete contraction and relaxation of all four heart chambers. |
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Term
| What is systole and what is happening within the chamber during this? |
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Definition
| Contraction, chamber pushes blood into next section. |
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Term
| What is diastole and what is happening within the chamber during this? |
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Definition
| Relaxation, chamber fills with blood |
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Term
| What is responsible for the absolute refractory period in cardiac muscles? |
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Definition
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Term
| What is another phrase for aortic systole? |
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Definition
|
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Term
| what are myocytes connected by? |
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Definition
|
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Term
| intercalated discs connections contain ____ and _____. |
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Definition
| multiple gap junctions and desmosomes |
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Term
| in the intercalated discs what do the multiple gap junctions allow to happen? |
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Definition
| The spreading of action potentials. |
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Term
| in the intercalated discs what do the desmosomes do? |
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Definition
| give structural integrity to the muscle sheet. |
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