C HAPTER 11: C ARDIOVASCULAR A NATOMY
AND P HYSIOLOGY
Urden: Critical Care Nursing, 9th Edition
MULTIPLE CHOICE
1. Depolarization of one m yocardial cell will likel y result in what
physiologic response?
a. Completion of the action potential in that cell before a new cell can
accept an impulse
b. Quick depolarization and spread to all of the heart
c. Depolarization of only cells superior to the initial depolarization
d. Quick depolarization of onl y cells inferior to the initial
depolarization
ANS: B
The cardiac muscle is a functional syncyt ium in which depolarization
started in any cardiac cell is quickl y spread to al l of the heart.
PTS: 1 DIF: Cognitive Level: Understanding REF: p.
171 OBJ: Nursing Process Step: N/A TOP: Cardiovascular
MSC: NC LEX: Physiologic Integrit y
2. What is the normal resting membrane potential of a m yocardial cell?
a. 10 to 20 mV
, b. 30 to 40 mV
c. –20 to –30 mV
d. –80 to –90 mV
ANS: D
In a m yocardial cell, the normal resting membrane potential is –80 to –
90 mV.
PTS: 1 DIF: Cognitive Level: Remembering REF: p. 173
OBJ: Nursing Process Step: N/A TOP: Cardiovascular
MSC: NC LEX: Physiologic Integr it y
3. Which phase is the final repolarization phase of the action potential?
a. Phase 1
b. Phase 2
c. Phase 3
d. Phase 4
ANS: C
The final repolarization phase is phase 3 of the action potential. Phases
1 and 2 (partial repolarization) occur as the AP slope returns to ward
zero. The plateau that follows is described as phase 2. In phase 4, the
AP returns to an RMP of –80 to –90 mV.
PTS: 1 DIF: Cognitive Level: Remembering REF: p. 174
OBJ: Nursing Process Step: N/A TOP: Cardiovascular
MSC: NC LEX: Physiologic Integ rit y
, 4. Which statement regarding the autonomic nervous system’s role in the
regulation of heart rate is true?
a. Parasympathetic influences increase heart rate.
b. Sympathetic influences are predominantl y present.
c. Parasympathetic influences are onl y compensatory.
d. Both sympathetic and parasympathetic influences are normally
active.
ANS: D
The parasympathetic nervous system and the sympathetic nervous
s ystem operate to create a balance between relaxation and fight-or-
flight readiness. They affect cardiovascular fu nction by slowing the
heart rate during periods of calm and increasing it in response to
s ympathetic stimulation.
PTS: 1 DIF: Cognitive Level: Understanding REF: p.
179 OBJ: Nursing Process Step: Assessment TOP:
Cardiovascular MSC: NC LEX: Physiologi c Integrit y
5. A patient is admitted with a diagnosis of acute m yocardial infarction. The
monitor pattern reveals bradycardia. Occlusion of which coronary artery
most likel y resulted in bradycardia from sinoatrial node ischemia?
a. Right
b. Left anterior descendin g
c. Circumflex
d. Dominant
ANS: A
AND P HYSIOLOGY
Urden: Critical Care Nursing, 9th Edition
MULTIPLE CHOICE
1. Depolarization of one m yocardial cell will likel y result in what
physiologic response?
a. Completion of the action potential in that cell before a new cell can
accept an impulse
b. Quick depolarization and spread to all of the heart
c. Depolarization of only cells superior to the initial depolarization
d. Quick depolarization of onl y cells inferior to the initial
depolarization
ANS: B
The cardiac muscle is a functional syncyt ium in which depolarization
started in any cardiac cell is quickl y spread to al l of the heart.
PTS: 1 DIF: Cognitive Level: Understanding REF: p.
171 OBJ: Nursing Process Step: N/A TOP: Cardiovascular
MSC: NC LEX: Physiologic Integrit y
2. What is the normal resting membrane potential of a m yocardial cell?
a. 10 to 20 mV
, b. 30 to 40 mV
c. –20 to –30 mV
d. –80 to –90 mV
ANS: D
In a m yocardial cell, the normal resting membrane potential is –80 to –
90 mV.
PTS: 1 DIF: Cognitive Level: Remembering REF: p. 173
OBJ: Nursing Process Step: N/A TOP: Cardiovascular
MSC: NC LEX: Physiologic Integr it y
3. Which phase is the final repolarization phase of the action potential?
a. Phase 1
b. Phase 2
c. Phase 3
d. Phase 4
ANS: C
The final repolarization phase is phase 3 of the action potential. Phases
1 and 2 (partial repolarization) occur as the AP slope returns to ward
zero. The plateau that follows is described as phase 2. In phase 4, the
AP returns to an RMP of –80 to –90 mV.
PTS: 1 DIF: Cognitive Level: Remembering REF: p. 174
OBJ: Nursing Process Step: N/A TOP: Cardiovascular
MSC: NC LEX: Physiologic Integ rit y
, 4. Which statement regarding the autonomic nervous system’s role in the
regulation of heart rate is true?
a. Parasympathetic influences increase heart rate.
b. Sympathetic influences are predominantl y present.
c. Parasympathetic influences are onl y compensatory.
d. Both sympathetic and parasympathetic influences are normally
active.
ANS: D
The parasympathetic nervous system and the sympathetic nervous
s ystem operate to create a balance between relaxation and fight-or-
flight readiness. They affect cardiovascular fu nction by slowing the
heart rate during periods of calm and increasing it in response to
s ympathetic stimulation.
PTS: 1 DIF: Cognitive Level: Understanding REF: p.
179 OBJ: Nursing Process Step: Assessment TOP:
Cardiovascular MSC: NC LEX: Physiologi c Integrit y
5. A patient is admitted with a diagnosis of acute m yocardial infarction. The
monitor pattern reveals bradycardia. Occlusion of which coronary artery
most likel y resulted in bradycardia from sinoatrial node ischemia?
a. Right
b. Left anterior descendin g
c. Circumflex
d. Dominant
ANS: A
