INTRODUCTION TO CRITICAL CARE NURSING 7TH EDITION SOLE TEST BANK
Chapter 07: Dysrhythmia Interpretation and Management Sole: Introduction to Critical Care Nursing, 7th Edition MULTIPLE CHOICE 1. The nurse is caring for a patient who is on a cardiac monitor. The nurse realizes that the sinus
node is the pacemaker of the heart because it is a. the fastest pacemaker cell in the heart. b. the only pacemaker cell in the heart. c. the only cell that does not affect the cardiac cycle. d. located in the left side of the heart. ANS: A
The cardiac cycle begins with an impulse that is generated from a small concentrated area of pacemaker cells high in the right atria called the sinoatrial node (sinus node or SA node). The SA node has the fastest rate of discharge and thus is the dominant pacemaker of the heart. The AV node has pacemaker properties and can discharge an impulse if the SA node fails. The ventricles have pacemaker capabilities if the sinus node or the AV node ceases to generate impulses. DIF: Cognitive Level: Remember/Knowledge REF: p. 90 OBJ: Explain the relationships between electrical and mechanical events in the heart. TOP: Nursing Process Step: N/A MSC: NCLEX Client Needs Category: Physiological Integrity 2. One of the functions of the atrioventricular (AV) node is to NURSINGTB.COM a. pace the heart if the ventricles fail. b. slow the impulse arriving from the SA node. c. send the impulse to the SA node. d. allow for ventricular filling during systole. ANS: B
The impulse from the SA node quickly reaches the atrioventricular (AV) node located in the area called the AV junction, between the atria and the ventricles. Here the impulse is slowed to allow time for ventricular filling during relaxation or ventricular diastole. The AV node has pacemaker properties and can discharge an impulse if the SA node (not the ventricle) fails. The electrical impulse is then rapidly conducted through the bundle of His to the ventricles (not the SA node) via the left and right bundle branches. DIF: Cognitive Level: Remember/Knowledge REF: p. 90 OBJ: Explain the relationships between electrical and mechanical events in the heart. TOP: Nursing Process Step: N/A MSC: NCLEX Client Needs Category: Physiological Integrity 3. The normal rate for the SA node when the patient is at rest is a. 40 to 60 beats per minute. b. 60 to 100 beats per minute. c. 20 to 40 beats per minute. d. more than100 beats per minute. ANS: B
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