PBS - 2.1 EKG review Quiz

How does the heart's electrical conduction system ensure coordinated contractions?

• By randomly activating the heart muscles

• By sequentially activating the atria and ventricles

• By causing the heart to beat faster during exercise

• By allowing the heart to rest between beats

What are the Bundle of His and its function?

• The Bundle of His conducts impulses from the AV node to the ventricles.

• The Bundle of His regulates blood flow in the heart.

• The Bundle of His is responsible for oxygen exchange in the lungs.

• The Bundle of His produces hormones that control heart rate.

What is depolarization in the context of the cardiac cycle?

• A process where cardiac muscle cells become less negative, leading to contraction.

• A phase where the heart relaxes and fills with blood.

• The electrical signal that initiates the heartbeat.

• A condition where the heart rate decreases significantly.

Tags

NGSS.HS-PS3-5

What is the function of the SA node in the heart?

• It regulates blood pressure.

• It acts as the natural pacemaker, initiating the electrical impulse that triggers heartbeats.

• It pumps oxygenated blood to the body.

• It filters impurities from the blood.

What is the difference between atrial and ventricular contraction?

• Atrial contraction occurs first, followed by ventricular contraction, ensuring efficient blood flow through the heart.

• Ventricular contraction occurs first, followed by atrial contraction, which is less efficient.

• Atrial and ventricular contractions occur simultaneously, maximizing blood flow.

• Atrial contraction is stronger than ventricular contraction, leading to more effective pumping.

What is the role of the cardiac cycle in heart function?

• The cardiac cycle refers to the sequence of events in one heartbeat, including contraction and relaxation phases.

• The cardiac cycle is the process of blood being pumped from the heart to the lungs only.

• The cardiac cycle involves the electrical signals that initiate heartbeats without any physical contraction.

• The cardiac cycle is the period of time when the heart is at rest and not pumping blood.

What does the P-wave on an EKG represent?

• The P-wave represents ventricular contraction.

• The P-wave correlates with atrium contraction and signals moving from the SA node to the AV node.

• The P-wave indicates the heart's resting state.

• The P-wave is associated with the repolarization of the ventricles.

Where are the Purkinje fibers located in the heart?

• In the atria

• At point I

• In the ventricles

• In the sinoatrial node

What does the T-wave on an EKG indicate?

• The T-wave correlates with ventricle repolarization.

• The T-wave indicates atrial depolarization.

• The T-wave represents ventricular contraction.

• The T-wave shows the heart rate.

What is repolarization in the context of the cardiac cycle?

• The process where cardiac muscle cells return to their resting negative state after contraction.

• The phase where the heart muscles contract and pump blood out of the heart.

• The period of time when the heart is at rest and filling with blood.

• The mechanism by which the heart rate increases during exercise.