Cardiac Action Potential Dynamics Quiz

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What is the function of the atria in the heart?

Attach the great veins and arteries at the base of the heart

Produce lubricating fluid in the pericardial cavity

Collect blood and push it into the lower chambers (correct)

Pump blood out to the body or lungs

Where is the epicardium located in the heart?

Attached at the base of the heart

Most superficial layer (correct)

Middle thickest layer

Between the parietal and visceral layers of the pericardium

Which vessel is responsible for carrying deoxygenated blood in the heart?

Pulmonary artery (correct)

Aorta

Superior vena cava

Pulmonary vein

What volume of fluid does the heart pump per minute?

52.5 L Signup and view all the answers

What is the size of a typical heart compared to?

Size of a fist Signup and view all the answers

Where are fat-filled grooves called sulci located in the heart?

On the surface of the heart containing coronary vessels Signup and view all the answers

What happens at 0mV in the heart's action potential?

Ca++ channels close and K+ channels open Signup and view all the answers

What is the purpose of the long refractory period in the heart?

To prevent premature contractions Signup and view all the answers

What would happen if the SA node fired 100 times per minute?

Heart rate would increase Signup and view all the answers

Which part of the heart's conduction system fires at the slowest rate?

Purkinje fibers Signup and view all the answers

What is the purpose of using electrodes in an ECG?

To record electrical signals of the heart Signup and view all the answers

What is the purpose of artificial pacemakers?

To ensure effective heart contractions Signup and view all the answers

During which phase of the cardiac cycle does systole occur?

Atrial systole Signup and view all the answers

What is the main function of an AED (Automated External Defibrillator)?

To correct fibrillations Signup and view all the answers

Which part of the heart undergoes repolarization during the T wave?

Ventricles Signup and view all the answers

What happens during ventricular diastole?

Relaxation and filling with blood Signup and view all the answers

Which phase of the cardiac cycle marks the end of ventricular relaxation?

Isovolumic ventricular relaxation phase Signup and view all the answers

Which heart sound is heard when the semilunar valves close?

S2 Signup and view all the answers

What does an S4 heart sound indicate?

Blood being pushed into a stiff ventricle Signup and view all the answers

What does the ejection fraction measure?

Percentage of blood pumped Signup and view all the answers

What is the formula for calculating cardiac output?

CO = HR * SV Signup and view all the answers

What effect does exercise have on stroke volume?

Increases it initially, then decreases it Signup and view all the answers

Which nerve dominates the autonomic tone of the heart?

Vagus nerve Signup and view all the answers

What happens when there is an increase in thyroid hormone levels?

Increases heart rate and contractility Signup and view all the answers

Which substances can decrease heart rate?

Hypoxia and alkalosis Signup and view all the answers

How does increased filling time affect stroke volume?

Increases it by allowing stronger contraction Signup and view all the answers

What is the main function of endothelins released by the endothelium?

Regulate growth patterns of cardiac muscle cells Signup and view all the answers

Which structure divides the heart into chambers?

Septum Signup and view all the answers

Where does the left atrium receive blood from?

Pulmonary veins Signup and view all the answers

Which valve separates the left atrium from the left ventricle?

Atrioventricular valve Signup and view all the answers

What is the main function of the moderator band in the heart?

To assist in cardiac conduction Signup and view all the answers

What is the purpose of anastomosis in coronary circulation?

To allow blood flow during blockages Signup and view all the answers

Which type of cells initiate and propagate the action potential through the heart?

Myocardial conducting cells Signup and view all the answers