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15 Cards in this Set
- Front
- Back
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Coronary venous blood from the left ventricle muscle returns to the right atrium by way of the ?
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coronary sinus
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Coronary venous blood from the right ventricular muscle returns through the ? that flow directly into the right atrium.
NOT BY CORONARY SINUS |
small cardiac veins
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The amount of coronary artery blood flow is closely matched to the amount of ?
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MVO2
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What are the two major determinants for coronary blood flow?
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Perfusion pressure
Coronary vascular resistance |
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What determines Perfusion Pressure?
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Aortic pressure
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True or False
Coronary ostia are partly occluded by the aortic valve cusps during ventricular systole. The full force of aortic systolic pressure is never conveyed to the coronary arteries. |
True
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? is an important determinant of coronary perfusion pressure.
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Proportion of time the heart spends in diastole
rapid heart rate = less coronary blood flow |
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Blood Flow (Q) within the coronary circulation is influenced by the magnitude of ?.
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Right Atrial Pressure
(increased right atrial pressure will cause FLOW to DECREASE) |
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Equation for blood flow within the coronary circulation:
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Q = (aortic pressure - right atrial pressure) + coronary vascular resistance
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What is the vascular resistance in the coronary circulation that is caused by compressing intramural coronary blood vessels that arise from the coronary arteries?
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Extracoronary Resistance
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Where is extracoronary resistance the greatest?
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Greatest in the left ventricle
(this is why LEFT coronary artery blood flow drops to almost ZERO during systole) |
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When is extracoronary resistance the highest?
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Ejection phase of Systole
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When is the extracoronary resistance the lowest?
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passive filling of Diastole
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Right ventricular hypertrophy can cause increased ventricular systolic pressure and thereby increase ? which will limit blood flow to the right ventricle during systole
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Increase Extracoronary resistance
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How does Left ventricular end-diastolic pressure affect coronary resistance?
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intramural capillaries at the subendocardial surface are compressed by the elevated intracavaity diastolic pressure.
this causes blood flow to decrease |
