unit 21: heart physiology

which component of the cardiac conduction system is known as the pacemaker?

SA node

Name the three deflection waves of a typical ECG.

P wave, QRS complex, and T wave

Which component of the cardiac conduction system extends through the interventricular septum toward the apex of the heart?

 Right and left bundle branches

Which component of the cardiac conduction system receives action potentials from the sinoatrial node?

AV node

Which component of the ECG represents the depolarization of the ventricles?

QRS complex

Which component of the ECG represents the repolarization of the ventricles?

 T wave

Which heart chamber lacks a group of pacemaker cells?

Left atrium

What is the anatomical term for the "pacemaker" of the heart?

SA node

The process of listening to heart sounds with a stethoscope is called

auscultation

What causes the heart sounds heard with a stethoscope?

The turbulence of blood against the closed valves

What action causes the first heart sound heard through a stethoscope?

Closing of the atrioventricular valves

What action causes the second heart sound heard through a stethoscope? 

Closing of the semilunar valves

The tracing of recorded electrical activity of the heart obtained by using electrodes on the skin is called an 

electrocardiogram

Identify the structure labeled "b."

AV node

Identify the structure labeled "e."

Right bundle branch

Identify the structure labeled "a."

SA node

Identify the structure labeled "c"

AV bundle

Identify the structure labeled "d."

left bundle branch

Identify the structure labeled "f"

terminal branches