SHARP EKG NEWEST ACTUAL WITH COMPLETE QUESTIONS
AND ANSWERS/ VERIFIED/GRADED A+/
What are the 3 functions of the AV node?
1. slow conduction of the electrical impulse through the AV
node to allow atria to empty into the ventricles (atrial kick)
2. to serve as a back pack pacemaker
3. protect ventricles from fast rates
After the delay in the AV node, where does the impulse go?
To the bundle of His
What is the function of the bundle of His?
The Bundle of His (AV Bundle) runs from the AV node through
the IV septum, splitting into R. and L. branches and eventually
breaking into Purkinje fibers as it spreads through the
ventricular walls
What is the rate of electrical impulse the Purkinje Fibers have?
30-40 bpm
Page 1 of 55
,What does the P wave represent?
atrial depolarization
When does atrial repolarization occur?
during the QRS complex
What does the QRS wave represent?
ventricular depolarization
What does the ST segment represent?
early ventricular repolarization
What are the two basic kinds of cardiac cells?
1. myocardial muscle cells
2. myocardial pacemaker cells
What are the 4 primary cell characteristics?
1. Automaticity
2. Excitability
Page 2 of 55
,3. Conductivity
4. Contractility
What are the two major ions that affect cardiac function?
1. sodium
2. potassium
What are the primary ions inside the cell?
Potassium
What are the primary ions outside the cell?
Sodium
Distribution of ions on either side of the membrane is
determined by which several factors?
1. membrane channels
2. concentration gradient
3. electrical gradient
4. sodium-potassium pump
Page 3 of 55
, Where is the SA node located?
In the upper wall of the right atrium/near the inlet of the
superior vena cava
What is the intrinsic rate of the SA node?
60-100 bpm
Pacemaker cells in the AV junction generate electrical
impulses at what rate?
40-60 bpm
What does the T wave represent?
ventricular repolarization
What does the QT interval represent?
the time of ventricular activity including both depolarization
and repolarization
What are the two refectory phases of the cardiac cycle?
1. Absolute refractory period
2. Relative refractory period
Page 4 of 55
AND ANSWERS/ VERIFIED/GRADED A+/
What are the 3 functions of the AV node?
1. slow conduction of the electrical impulse through the AV
node to allow atria to empty into the ventricles (atrial kick)
2. to serve as a back pack pacemaker
3. protect ventricles from fast rates
After the delay in the AV node, where does the impulse go?
To the bundle of His
What is the function of the bundle of His?
The Bundle of His (AV Bundle) runs from the AV node through
the IV septum, splitting into R. and L. branches and eventually
breaking into Purkinje fibers as it spreads through the
ventricular walls
What is the rate of electrical impulse the Purkinje Fibers have?
30-40 bpm
Page 1 of 55
,What does the P wave represent?
atrial depolarization
When does atrial repolarization occur?
during the QRS complex
What does the QRS wave represent?
ventricular depolarization
What does the ST segment represent?
early ventricular repolarization
What are the two basic kinds of cardiac cells?
1. myocardial muscle cells
2. myocardial pacemaker cells
What are the 4 primary cell characteristics?
1. Automaticity
2. Excitability
Page 2 of 55
,3. Conductivity
4. Contractility
What are the two major ions that affect cardiac function?
1. sodium
2. potassium
What are the primary ions inside the cell?
Potassium
What are the primary ions outside the cell?
Sodium
Distribution of ions on either side of the membrane is
determined by which several factors?
1. membrane channels
2. concentration gradient
3. electrical gradient
4. sodium-potassium pump
Page 3 of 55
, Where is the SA node located?
In the upper wall of the right atrium/near the inlet of the
superior vena cava
What is the intrinsic rate of the SA node?
60-100 bpm
Pacemaker cells in the AV junction generate electrical
impulses at what rate?
40-60 bpm
What does the T wave represent?
ventricular repolarization
What does the QT interval represent?
the time of ventricular activity including both depolarization
and repolarization
What are the two refectory phases of the cardiac cycle?
1. Absolute refractory period
2. Relative refractory period
Page 4 of 55
