# data[].attributes.headline
Why the ventricles don't contract before the atria have completely contracted ?

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Why the ventricles don't contract before the atria have completely contracted ?

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Due to AVN delay

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What type of receptors is found the ventricles?

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What type of receptors is found the ventricles?

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Beta-1 receptors

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What is the effect of thyroxin hormones on the heart rate?

# data[].attributes.subject
What is the effect of thyroxin hormones on the heart rate?

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Increase sensitivity of Beta-1 receptors to catelcolamines

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Why is the heart rate at rest slower than the inherent rate of SAN ?

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Why is the heart rate at rest slower than the inherent rate of SAN ?

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Due to the parasympathetic effect (vagal tone)

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Increased end diastolic volume (EDV)

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What happens if you stands still for a long time?

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What happens if you stands still for a long time?

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Decrease the venous return

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In which cardiac phase the pressure is close to zero?

# data[].attributes.subject
In which cardiac phase the pressure is close to zero?

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Ventricular filling

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In a heart at rest, how much is the stroke volume?

# data[].attributes.subject
In a heart at rest, how much is the stroke volume?

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80 ml

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Stroke Volume/ End diastolic volume

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In the ECG, the QRS complex represents what?

# data[].attributes.subject
In the ECG, the QRS complex represents what?

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Ventricular depolarization

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How much of the blood is found in veins?

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How much of the blood is found in veins?

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60%

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In which phases of the cardiac cycle  all valves are closed:

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In which phases of the cardiac cycle  all valves are closed:

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Isometric contraction and relaxation phases

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effect of sympathetic stimulation on the Heart rate:

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effect of sympathetic stimulation on the Heart rate:

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decrease of K+ efflux , increase in of Na+ and Ca++ influx

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The plateau in contractile cardiac cells' action potential is characterized by what?

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The plateau in contractile cardiac cells' action potential is characterized by what?

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Opening of slow Ca++ and K+ channels at the same time

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In the heart, what is the determinant of the after-load?

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In the heart, what is the determinant of the after-load?

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Arterial blood pressure

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What causes phase 0 in the conduction action potential?

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What causes phase 0 in the conduction action potential?

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Opening of long lasting (L-type) Ca++ channels

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What is the effect of the parasympathetic supply on the heart rate ?

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What is the effect of the parasympathetic supply on the heart rate ?

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Negative chronotropic effect

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Recent myocardial infarction

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Which phase in the cardiac cycle is described from B to C ?

# data[].attributes.subject
Which phase in the cardiac cycle is described from B to C ?

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Isometric contraction phase

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Which heart sound is produced at the beginning of the ventricular systole ?

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Which heart sound is produced at the beginning of the ventricular systole ?

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First heart sound

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What is the pressure in the right ventricle during the cardiac cylce ?

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What is the pressure in the right ventricle during the cardiac cylce ?

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25/0 mmHg

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The c wave in atrial pressure is due to:

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The c wave in atrial pressure is due to:

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Closure and bulging of the AV valves into the atria

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Cardiac output in relation to the surface area

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In severe parasympathetic stimulation, the heart is not significantly effected, why?

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In severe parasympathetic stimulation, the heart is not significantly effected, why?

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Because there is no vagal supply to the ventricles

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What is the equation that describes the cardiac output?

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What is the equation that describes the cardiac output?

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Stroke volume * Heart rate