Question 1

In which of the following clinical conditions are calcium channel blockers indicated?

Accepted Answer

A)  Coronary artery disease 
B)  Hypotension 
C)  Asthma 
D)  Congestive heart failure 
A)  Coronary artery disease 
B)  Hypotension 
C)  Asthma 
D)  Congestive heart failure A

Question 2

If AV impulses fail to reach the ventricles after few seconds, what will the heart rate be?

Accepted Answer

A)  70 to 80 beats/min 
B)  15 to 40 beats/min 
C)  40 to 60 beats/min 
D)  50 to 70 beats/min 
A)  70 to 80 beats/min 
B)  15 to 40 beats/min 
C)  40 to 60 beats/min 
D)  50 to 70 beats/min B

Question 3

What explains the increase in the SA nodal firing rate caused by sympathetic stimulation?

Accepted Answer

A)  Increased permeability to K+ 
B)  Increased intracellular K+ 
C)  Increased Cl- inside the cell 
D)  Increased permeability to Ca++ 
A)  Increased permeability to K+ 
B)  Increased intracellular K+ 
C)  Increased Cl- inside the cell 
D)  Increased permeability to Ca++ D

Question 4

Which of the following structures conducts SA nodal impulses to the left atrium?

Accepted Answer

A)  AV bundle 
B)  Bachmann's bundle 
C)  Right bundle branch 
D)  Left bundle branch 
A)  AV bundle 
B)  Bachmann's bundle 
C)  Right bundle branch 
D)  Left bundle branch

Question 5

Which of the following are known effects of catecholamines?
I.They increase the influx of Ca++ into the myocardial cell during the plateau phase of the action potential.
II.They activate beta receptors in the cardiac cell membrane.
III.They raise intracellular levels of cyclic AMP.
IV.They raise intracellular levels of cyclic GMP.

Accepted Answer

A)  I, II 
B)  III, IV 
C)  I, II, III, IV 
D)  I, II, III 
A)  I, II 
B)  III, IV 
C)  I, II, III, IV 
D)  I, II, III

Question 6

What is the normal sinus rhythm rate?

Accepted Answer

A)  40 to 59 beats/min 
B)  60 to 69 beats/min 
C)  70 to 80 beats/min 
D)  >100 beats/min 
A)  40 to 59 beats/min 
B)  60 to 69 beats/min 
C)  70 to 80 beats/min 
D)  >100 beats/min

Question 7

If the SA node stops firing, what will be the expected heart rate?

Accepted Answer

A)  70 to 80 beats/min 
B)  80 to 100 beats/min 
C)  40 to 60 beats/min 
D)  50 to 70 beats/min 
A)  70 to 80 beats/min 
B)  80 to 100 beats/min 
C)  40 to 60 beats/min 
D)  50 to 70 beats/min

Question 8

Which of the following are properties of the cardiac tissue?
I.Automaticity
II.Rhythmicity
III.Excitability
IV.Contractility

Accepted Answer

A)  I, II 
B)  III, IV 
C)  I, II, III, IV 
D)  II, III 
A)  I, II 
B)  III, IV 
C)  I, II, III, IV 
D)  II, III

Question 9

Which of the following are components of the AV nodal system?
I.Bachmann's bundle
II.Junctional fibers
III.Node proper
IV.AV bundle

Accepted Answer

A)  I, II 
B)  II, III, IV 
C)  I, II, III, IV 
D)  II, III 
A)  I, II 
B)  II, III, IV 
C)  I, II, III, IV 
D)  II, III

Question 10

Which of the following may cause premature beats?
I.Local areas of tissue hypoxia
II.Mechanical irritation of the tissue
III.Toxic irritation
IV.Drugs

Accepted Answer

A)  I, II 
B)  III, IV 
C)  I, II, III, IV 
D)  II, III 
A)  I, II 
B)  III, IV 
C)  I, II, III, IV 
D)  II, III

Question 11

Which of the following agents are useful in the treatment of ectopic foci?
I.Lidocaine
II.Amiodarone
III.Beta blockers
IV.Calcium channel blockers

Accepted Answer

A)  I, II 
B)  III, IV 
C)  I, II, III, IV 
D)  II, III 
A)  I, II 
B)  III, IV 
C)  I, II, III, IV 
D)  II, III

Question 12

Which of the following conditions are associated with increased heart muscle excitability?
I.Hypocalcemia
II.Hyperkalemia
III.Hypercalcemia
IV.Hypokalemia

Accepted Answer

A)  I, II 
B)  III, IV 
C)  I, II, III, IV 
D)  II, III 
A)  I, II 
B)  III, IV 
C)  I, II, III, IV 
D)  II, III

Question 13

What is the name of the ventricular rhythm associated with the pacemaker function taken over by the Purkinje system?

Accepted Answer

A)  Ventricular arrhythmia 
B)  Ventricular escape 
C)  Dominant rhythm 
D)  Ventricular ectopy 
A)  Ventricular arrhythmia 
B)  Ventricular escape 
C)  Dominant rhythm 
D)  Ventricular ectopy

Question 14

Which of the following phenomena is responsible for the initiation of muscle contraction?

Accepted Answer

A)  Electrochemical repolarization 
B)  Membrane depolarization 
C)  Membrane repolarization 
D)  Membrane permeability 
A)  Electrochemical repolarization 
B)  Membrane depolarization 
C)  Membrane repolarization 
D)  Membrane permeability

Question 15

Changes in which extracellular ion has little effect on the RMP of cardiac muscle?

Accepted Answer

A)  Na+ 
B)  K+ 
C)  Ca++ 
D)  Cl- 
A)  Na+ 
B)  K+ 
C)  Ca++ 
D)  Cl-

Question 16

What explains the AV block caused by vagal stimulation?

Accepted Answer

A)  Increased permeability to K+ 
B)  Increased intracellular K+ 
C)  Increased Na+ inside the cell 
D)  Increased permeability to Ca+ 
A)  Increased permeability to K+ 
B)  Increased intracellular K+ 
C)  Increased Na+ inside the cell 
D)  Increased permeability to Ca+

Question 17

Which of the following statements are true of potassium?
I.Hyperkalemia decreases the heart rate.
II.Hyperkalemia decreases the stroke volume.
III.Hyperkalemia causes heart block.
IV.Hyperkalemia increases heart conductivity.

Accepted Answer

A)  I, II, III 
B)  III, IV 
C)  I, II, III, IV 
D)  II, III 
A)  I, II, III 
B)  III, IV 
C)  I, II, III, IV 
D)  II, III

Question 18

Which of the following areas of the heart is the most excitable?

Accepted Answer

A)  Bundle branch 
B)  Purkinje fibers 
C)  AV node 
D)  SA node 
A)  Bundle branch 
B)  Purkinje fibers 
C)  AV node 
D)  SA node

Exam 18: Cardiac Electrophysiology

In which of the following clinical conditions are calcium channel blockers indicated?

If AV impulses fail to reach the ventricles after few seconds, what will the heart rate be?

What explains the increase in the SA nodal firing rate caused by sympathetic stimulation?

Which of the following structures conducts SA nodal impulses to the left atrium?

What is the normal sinus rhythm rate?

If the SA node stops firing, what will be the expected heart rate?

Which of the following are properties of the cardiac tissue? I.Automaticity II.Rhythmicity III.Excitability IV.Contractility

Which of the following are components of the AV nodal system? I.Bachmann's bundle II.Junctional fibers III.Node proper IV.AV bundle

Which of the following may cause premature beats? I.Local areas of tissue hypoxia II.Mechanical irritation of the tissue III.Toxic irritation IV.Drugs

Which of the following agents are useful in the treatment of ectopic foci? I.Lidocaine II.Amiodarone III.Beta blockers IV.Calcium channel blockers

Which of the following conditions are associated with increased heart muscle excitability? I.Hypocalcemia II.Hyperkalemia III.Hypercalcemia IV.Hypokalemia

What is the name of the ventricular rhythm associated with the pacemaker function taken over by the Purkinje system?

Which of the following phenomena is responsible for the initiation of muscle contraction?

Changes in which extracellular ion has little effect on the RMP of cardiac muscle?

What explains the AV block caused by vagal stimulation?

Which of the following statements are true of potassium? I.Hyperkalemia decreases the heart rate. II.Hyperkalemia decreases the stroke volume. III.Hyperkalemia causes heart block. IV.Hyperkalemia increases heart conductivity.

Which of the following areas of the heart is the most excitable?

The Airways and Alveoli

The Lungs and Chest Wall

Mechanics of Ventilation

Ventilation

Pulmonary Function Measurements

Pulmonary Blood Flow

Gas Diffusion

Oxygen Equilibrium and Transport

Carbon Dioxide Equilibrium and Transport

Acid-Base Regulation

Control of Ventilation

Ventilation-Perfusion Relationships

Clinical Assessment of Acid-Base and Oxygenation Status

Physiological Basis for Oxygenation and Lung Protection Strategies

Physiology of Sleep Disordered Breathing

Fetal and Newborn Cardiopulmonary Physiology

Functional Anatomy of the Cardiovascular System

The Electrocardiogram and Cardiac Arrhythmias In Adults

Control of Cardiac Output and Hemodynamic

Filtration, Urine Formation, and Fluid Regulation

Electrolyte and Acid-Base Regulation

Cardiopulmonary Response to Exercise in Health and Disease

Aging and the Cardiopulmonary System

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