What is the primary role of the SA node in the heart?

• It collects oxygenated blood.

• It pumps blood to the lungs.

• It prevents backflow of blood.

• It acts as the heart's natural pacemaker.

Where is the AV node located?

• Between the left atrium and left ventricle.

• At the border of the right atrium and right ventricle.

• In the upper wall of the left ventricle.

• Near the entrance of the superior vena cava.

What happens if the SA node fails to generate a strong impulse?

• The AV node will not conduct any impulse.

• The Purkinje fibers take over as the pacemaker.

• The AV node may generate its own impulse.

• The heart will immediately stop.

What does the P wave in an EKG represent?

• Ventricular depolarization

• Ventricular repolarization

• Atrial depolarization

• Atrial repolarization

Which structure masks atrial repolarization in an EKG?

• P wave

• T wave

• ST segment

• QRS complex

What is the normal range for a PR interval on an EKG?

• 0.06 to 0.12 seconds

• 0.12 to 0.20 seconds

• 0.20 to 0.40 seconds

• 0.01 to 0.05 seconds

What could a prolonged QRS complex indicate?

• A premature ventricular contraction (PVC)

• A heart block

• A junctional rhythm

• Normal heart function

What does a regular rhythm on an EKG indicate?

• The heart is experiencing arrhythmia.

• The heart rate is constant.

• The heart rate is above 100 bpm.

• The intervals between R's are varying.

How is the heart rate calculated using the 6-second method?

• Count QRS complexes and divide by 10

• Count T waves and divide by 6

• Count P waves and multiply by 10

• Count R waves and multiply by 10

What is the significance of the big box method in calculating heart rate?

• It calculates the heart rate based on T waves.

• It provides a more accurate heart rate for regular rhythms.

• It is used when the EKG strip is not 6 seconds.

• It is used for irregular rhythms.