Term
| What muscle is unique to the heart? |
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Definition
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Term
| Name four properties of cardiac muscle |
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Definition
| striated, have one nucleus, contraction is involuntary, Y-shaped |
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Term
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Definition
| a collection of uniquely structured cardiac cells that spontaneously initiate electrical impulses without stimulation from nerves. The initiation occurs rhythmically. |
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Term
| Why does the heart contraction happens so fast? |
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Definition
| Because of gap junctions that allow electric charges to flow freely between cells |
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Term
| What is the contraction of the heart muscles called? |
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Definition
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Term
| what is the relaxation of the heart muscles called? |
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Definition
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Term
| name two features of the AV node that cause the delay of contraction after the SA node. |
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Definition
| fewer gap junctions, smaller cells so do not conduct as quickly |
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Term
| What is the function of the purkenje fibres in the ventricles? |
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Definition
| conduct the signal to contract rapidly through the ventricles |
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Term
| What causes the two sounds of the heartbeat |
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Definition
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Term
| What are some factors affecting the heart rate, name three. |
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Definition
| exercise, intensity of exercise, breath-holding and exposure to cold stimulus. |
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Term
| what is ventricular fibrillation? |
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Definition
| twitching of the ventricles due to rapid and chaotic contraction of individual muscle cells. |
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Term
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Definition
| hardening of the arteries caused by the formation of plaque |
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Term
| Name four possible causes correlated with thrombosis and hypertension, and heart failures. |
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Definition
| Having parents who had heart attacks, Old age, females post menopause, Males, Smoking, High salt and alcohol diets, stress, Eating too much saturated fat and cholesterol, Height |
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Term
| how are blood pressure measurements calculated. |
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Definition
| a fraction, where the higher number refers to the pressure in the artery during systole and the lower number refers to pressure during diastole. units = mm Hg. |
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