Question 1

The pacemaker that fires at 20 to 40 beats per minute is:

Accepted Answer

A)   the SA node.
B)   the bundle of His.
C)   the AV node.
D)   Purkinje's network. D

Question 2

Which part of the conduction system has a firing rate of 60 to 100?

Accepted Answer

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

Question 3

The three-lead EKG strip is representative of the mechanical activity of the heart.

Accepted Answer

A) True 
 B)False  False

Question 4

The node that is located just above the tricuspid valve is the:

Accepted Answer

A)   AV node.
B)   SA node.
C)   Purkinje node.
D)   central node.

Question 5

Nodes and bundles are located primarily beneath the:

Accepted Answer

A)   myocardium.
B)   epicardium.
C)   pericardium.
D)   endocardium.

Question 6

The area where the internodal pathways join the bundle of His is:

Accepted Answer

A)   Purkinje's network.
B)   the left bundle branch.
C)   the AV junction.
D)   the right bundle branch.

Question 7

The bundle of His lies at the ________ of the interventricular septum.

Accepted Answer

A)   bottom
B)   top
C)   right
D)   left

Question 8

The internodal tracts consist of anterior,middle,and posterior. They are also known as all of the following EXCEPT:

Accepted Answer

A)   Bachmann's bundle.
B)   Thorel's pathway.
C)   Wenckebach's bundle.
D)   Beasley's pathway.

Question 9

A(n)________ pathway may be defined as an irregular muscle connection between the atria and the ventricles that bypasses the AV node.

Accepted Answer

A)   universal
B)   Thorel's
C)   accessory
D)   conductive

Question 10

The SA node impulses result in:

Accepted Answer

A)   diastole.
B)   depolarization.
C)   repolarization.
D)   All of the above

Question 11

Bachmann's bundle is located in the:

Accepted Answer

A)   left atrium.
B)   right ventricle.
C)   top of right atrium.
D)   left ventricle.

Question 12

The bundle of His is also traditionally referred to as the ________ bundle.

Accepted Answer

A)   universal
B)   simple
C)   common
D)   dedicated

Question 13

If the vagus nerve is stimulated,the heart rate will:

Accepted Answer

A)   increase.
B)   decrease.

Question 14

In the normal heart,this is the ONLY pathway between the atria and ventricles.

Accepted Answer

A)   Right bundle branch
B)   SA node
C)   AV node
D)   Left bundle branch

Question 15

It is generally believed that a bit less than ________ of the cells are actual pacemaker cells.

Accepted Answer

A)   50%
B)   25%
C)   85%
D)   75%

Exam 4: The Electrical Conduction System

The pacemaker that fires at 20 to 40 beats per minute is: