a.Decreased myocardial contraction b.Decreased heart rate c.Increased cardiac conduction d.Increased intranodal conduction time C. Increased cardiac conduction A 50-year-old female received trauma to the chest that caused severe impairment of the primary pacemaker cells of the heart. Which of the following areas received the greatest damage? a.Atrioventricular (AV) node b.Sinoatrial (SA) node c.Bundle of His d.Ventricles B. Sinoatrial node (SA) A 54-year-old male is diagnosed with left bundle branch block. Which of the following structures would not receive an electrical impulse? a.Atrioventricular (AV) node b.Sinoatrial (SA) node c.Bundle of His d.The left ventricle D. the left ventricle Which information by the nurse indicates a good understanding of depolarization? Depolarization of a cardiac muscle cell occurs as the result of: a.A decrease in the permeability of the cell membrane to ions
b.The rapid movement of ions across the cell membrane c.A blockade by calcium ions d.Stimuli instigated during the refractory period B. the rapid movement of ions across the cell membrane A cardiologist is teaching about the period that follows depolarization of the myocardium and represents a period during which no new cardiac potential can be propagated. What is the cardiologist describing? a.resting b.absolute refractory c.threshold d. hyperpolarization b. absolute refractory The nurse is reviewing a normal electrocardiogram. The nurse assesses the PR interval because it represents: A. Atrial depolarization B. Ventricular depolarization C. Onset of atrial activation to onset of ventricular activity D. "Electrical systole" of the ventricles C. the onset of atrial activation to onset of ventricular activity The _____ represents the sum of all ventricular muscle cell depolarization. a.PR interval b.QRS complex c.QT interval d.P wave B. QRS complex The cardiac electrical impulse normally begins spontaneously in the sinoatrial (SA) node because it: a. Has a superior location in the right atrium. b. Is the only area of the heart capable of spontaneous depolarization. c. Has rich sympathetic innervation via the vagus nerve. d. Depolarizes more rapidly than other automatic cells of the heart. D The electrical impulse normally begins in the SA node because its cells depolarize more rapidly than other automatic cells. This selection is the only option that accurately explains why cardiac electrical impulses normally begin spontaneously in the SA node A 28-year-old female with seizure disorder has a vagus nerve stimulator implanted to help control seizure activity. Which of the following would the nurse also expect to occur? a.Increased speed of cardiac cycle b.Increased cardiac contractility c.Decreased vasodilation d.Decreased cardiac conduction D. decreased cardiac conduction.
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- Fall '17
- keisha lovence