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NURS 231 EXAM 4
NURS 231 REAL EXAM 4 STUDY
GUIDE UPDATED 2025/ 2026 –
MEDICAL-SURGICAL NURSING
TESTBANK EXPERT VERIFIED
QUESTIONS AND APPROVED
ANSWERS FOR GUARANTEED PASS
GRADED A+
Automaticity
----Solution----The ability of the heart to generate and conduct electrical
impulses on its own; only pacemaker cells
These Sites Have Pacemaker Cells. . .
----Solution----SA Node
AV Node
Perkinje Fiber cells
Excitability
----Solution----the ability of the cardiac cells to respond to an electrical
impulse; this characteristic is shared by all cardiac cells;
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They get excited by cells around them
Conductivity
----Solution----the ability of cardiac cells to conduct an electrical
impulse; this characteristic is shared by all cardiac cells
They conduct electrical impulses from the cells around them
Contractility
----Solution----the ability of cardiac cells to cause cardiac muscle
contraction; this characteristic is specific to the muscle cells
Na and K
----Solution----the two major ions that affect cardiac function;
(depolarization and repolarization)
K functions inside of the cell while Na functions outside of the cell
Resting State
----Solution----this is a polarized cell; K is on the inside of the cell and
Na on the outside. There is no electrical discharge happening so the line
is flat on an EKG strip
Depolarization
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----Solution----The process during the action potential when sodium is
rushing into the cell causing the interior to become more positive.
Muscle contraction follows.
This is an electrical event that results in muscle contraction, a
mechanical event.
P Wave in the atria and QRS in the ventricle
SA Node
----Solution----
-Normal pacemaker of the heart; located in the right atrium
-initiates impulses of 60-100 bpm
-This is what we want, the sequence goes from atria to ventricle
AV Node
----Solution-----located in the right atrium along the lower part of the
interatrial septum
-Can act as a back up pacemaker and initiate impulses if needed
-Rate is 40-60 bpm
-*AV delay* is a pause that allows the atria to completely squeeze and
empty its blood volume into the ventricles; the stimulus s l o w s in the
AV node which causes this
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-can also block some impulses from being conducted to the ventricles
when the atria rate is rapid, protecting the ventricles from dangerously
fast rates
Bundle of His
----Solution-----Short and thick accumulation of nerve tissue/electrical
tissue
-branches into a right and left bundle branch
-Left bundle branch again divides into fascicles (anterior and posterior)
-the left side has much more to areas to pump to, so that is why it further
divides
Purkinjie Fibers
----Solution-----fibers that serve to conduct electrical impulses through
the right and left ventricles
-Has pacemaker cells that can initiate impulses at a rate of 20-40 bpm
(backup pacemaker)
-These invade the cardiac muscle and get electrical impulses to the very,
very end of the cardiac tissue
Lead
----Solution-----a view of the heart's *electrical activity*
-Between 2 points or "poles"
-Negative and positive poles
-You only need ONE lead to monitor for dysrhythmias
NURS 231 EXAM 4
NURS 231 REAL EXAM 4 STUDY
GUIDE UPDATED 2025/ 2026 –
MEDICAL-SURGICAL NURSING
TESTBANK EXPERT VERIFIED
QUESTIONS AND APPROVED
ANSWERS FOR GUARANTEED PASS
GRADED A+
Automaticity
----Solution----The ability of the heart to generate and conduct electrical
impulses on its own; only pacemaker cells
These Sites Have Pacemaker Cells. . .
----Solution----SA Node
AV Node
Perkinje Fiber cells
Excitability
----Solution----the ability of the cardiac cells to respond to an electrical
impulse; this characteristic is shared by all cardiac cells;
,2|Page
They get excited by cells around them
Conductivity
----Solution----the ability of cardiac cells to conduct an electrical
impulse; this characteristic is shared by all cardiac cells
They conduct electrical impulses from the cells around them
Contractility
----Solution----the ability of cardiac cells to cause cardiac muscle
contraction; this characteristic is specific to the muscle cells
Na and K
----Solution----the two major ions that affect cardiac function;
(depolarization and repolarization)
K functions inside of the cell while Na functions outside of the cell
Resting State
----Solution----this is a polarized cell; K is on the inside of the cell and
Na on the outside. There is no electrical discharge happening so the line
is flat on an EKG strip
Depolarization
,3|Page
----Solution----The process during the action potential when sodium is
rushing into the cell causing the interior to become more positive.
Muscle contraction follows.
This is an electrical event that results in muscle contraction, a
mechanical event.
P Wave in the atria and QRS in the ventricle
SA Node
----Solution----
-Normal pacemaker of the heart; located in the right atrium
-initiates impulses of 60-100 bpm
-This is what we want, the sequence goes from atria to ventricle
AV Node
----Solution-----located in the right atrium along the lower part of the
interatrial septum
-Can act as a back up pacemaker and initiate impulses if needed
-Rate is 40-60 bpm
-*AV delay* is a pause that allows the atria to completely squeeze and
empty its blood volume into the ventricles; the stimulus s l o w s in the
AV node which causes this
, 4|Page
-can also block some impulses from being conducted to the ventricles
when the atria rate is rapid, protecting the ventricles from dangerously
fast rates
Bundle of His
----Solution-----Short and thick accumulation of nerve tissue/electrical
tissue
-branches into a right and left bundle branch
-Left bundle branch again divides into fascicles (anterior and posterior)
-the left side has much more to areas to pump to, so that is why it further
divides
Purkinjie Fibers
----Solution-----fibers that serve to conduct electrical impulses through
the right and left ventricles
-Has pacemaker cells that can initiate impulses at a rate of 20-40 bpm
(backup pacemaker)
-These invade the cardiac muscle and get electrical impulses to the very,
very end of the cardiac tissue
Lead
----Solution-----a view of the heart's *electrical activity*
-Between 2 points or "poles"
-Negative and positive poles
-You only need ONE lead to monitor for dysrhythmias
