E) heart block.
2. In the condition known as complete heart block, what happens?
A) Coronary arteries are blocked by plaques, preventing blood and oxygen from reaching the myocardial contractile cells.
B) Electrical signals from the SA node never reach the ventricles, so the contraction of the atria is not coordinated with the contraction of the ventricles.
C) The fibrous skeleton of the heart breaks down, interfering with the passage of blood from the atria to the ventricles.
D) The mitral valve leaflets calcify and close, preventing blood from being pumped efficiently by the left side of the heart.
E) Blood flow through the foramen ovale is blocked.
3. ECGs
A) provide direct information about the heart function.
B) are most useful in diagnosing heart murmurs.
C) show the "summed" electrical potentials generated by all cells of the heart.
D) have two major components: waves and nodes.
E) measure the mechanical activity of the heart.
4. The P wave of an ECG corresponds to
A) the depolarization of the atria.
B) the progressive wave of ventricular depolarization.
C) the repolarization of the ventricles.
D) atrial repolarization.
E) None of the answers are correct.
5. The QRS complex of an ECG corresponds to
A) the depolarization of the atria.
B) ventricular depolarization and atrial repolarization
C) the repolarization of the ventricles.
D) atrial repolarization.
E) None of the answers are correct.
6. Ventricular contraction
A) begins during the first part of the P wave.
B) begins just after the T wave.
C) begins just after the Q wave.
D) begins during the latter part of the P wave.
E) None of the answers are correct.
7. Atrial contraction
A) begins during the first part of the P wave.
B) begins just after the T wave.
C) begins just after the Q wave.
D) begins during the latter part of the P wave.
E) None of the answers are correct.