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30 Cards in this Set
- Front
- Back
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Area X Velocity = ?
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FLOW
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How do the volume-pressure curves of the systemic arterial system differ from systemic venous system?
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A small change in arterial volume translates to a large change in pressure
Veins are much more compliant, so it takes a much greater change in volume to illicit a significant change in pressure |
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In which direction does the contraction of the heart proceed in?
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Apex--> Base
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What ion is key for the action potentials of the SA and AV node?
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Na (it slowly leaks until it hits the threshold)
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4 main steps of cardiac excitation and contraction coupling?
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1. Action Potential/Ion Movement
2. Myocyte Contraction 3. Ca in cytoplasm wanes 4. Myocyte Relaxation |
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Which Ions are responsible for Action Potential propagation?
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Na (rapid)
Ca (slower) |
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How do the ions --> contraction?
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Ca induces further Ca release from the Sarcoplasmic Reticulum
Ca also interacts w/ Troponin C which interacts w/ A/M filaments |
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How is the action potential reset?
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Ca is resequestered in SR
K efflux Na/K ATPase Activated |
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How is Ca removed?
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Na/Ca Exchanger
CaATPase |
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What is happening to create the 1st heart sound?
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Aortic Valve Opening
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What is happening to create the second heart sound?
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Aortic Valve is Closing
A-V opens |
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What creates the 3rd heart sound?
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Ventricular Filling
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When is Coronary Blood Flow highest?
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During Diastole (when the heart is relaxed)
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Coronary Circulation receives what % of cardiac output?
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5-10%
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Coronary Circulation consumes what % of total body O2?
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10-20%
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How is the discrepancy between volume and O2 consumption explained?
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There is almost complete extraction of O2 from the hemoglobin of the coronary blood flow
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The Coronary Cardiac Oxygen Consumption is proportional to?
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Heart Rate
Intramyocardial Tension (T) Contractility |
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How the heck do you figure out the Intramyocardial Tension/
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(Pressure X Radius)/ Wall thickness
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What does starling's law say?
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Prestretched muscle contracts more forcefully
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Cardiac Output = ??
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Stroke Volume X HR
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Stroke Volume =?
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End Diastolic Volume - End Systolic Volume
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Ejection Fraction = ?
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Stroke Volume / End Diastolic Volume
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Autonomic Input to the SA and AV nodes?
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PSNS from Vagus to both
SNS to both |
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What other autonomic input does the heart receive?
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There is sympathetic innervation that goes to the ventricular myocardium
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SNS effects on Beta vs Alpha Receptors
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BETA:
Inc HR Inc Contractility Vasodilate ALPHA: Vasoconstrict Inc Contractility |
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What is BP/Flow?
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Resistance
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What is pussy willow's law (poiseuille's)?
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Flow = (pie X pressure X raduis ^4)/ (8 X Length X viscosity)
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Blood-borne Vasoconstrictors?
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Endothelial Cells:
Ang II Endothelin Platelets: Thromboxane |
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Blood-borne vasodilators?
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Endothelial Cells:
NO Prostacyclin |
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Afferent Routes of the pressure sensors?
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Aortic Barorecptors-->Vagus nerve-->Brain Stem
Carotid Body and Sinus-->Hering's Nerve-->Glossopharyngeal N-->BS |
