CONDUCTION THROUGH THE HEART

The natural pacemaker of the heart is the

• AV node (Atrioventricular node)

• SA node (Sinoatrial node)

• Brainstem

• Purkinje fibers

Depolarization of a heart chamber such as the left atrium means the left atrium has

• contracted

• relaxed

The P wave on an ECG printout represents

• contraction of the ventricles

• relaxation of the ventricles

• contraction of the atria

• relaxation of the atria

The T wave on an ECG printout represents

• contraction of the ventricles

• relaxation of the ventricles

• contraction of the atria

• relaxation of the atria

Which of the following define diastole and systole

• systole is the contraction of the heart and diastole is the relaxation of the heart
• diastole is the contraction of the heart and systole is the relaxation of the heart
• diastole and systole are both contractions of the heart
• diastole and systole are both relaxation phases of the heart