Studied by 18 people
What is 1 of the cardiac conduction system?
Sinoatrial (SA) node
What is 2 of the cardiac conduction system?
Internodal pathways
What is 3 of the cardiac conduction system?
Atrioventricular (AV) node
What is 4 of the cardiac conduction system?
Bundle of His
What is 5 of the cardiac conduction system?
Right and left bundle branches
What is 6 of the cardiac conduction system?
Purkinje fibers
electro =
electrical
cardio =
heart
gram =
drawing
What does an ECG measure?
All of the electrical activity generated by heart at a given time (sum of all action potentials)
Where is the P Wave and what happens during this?
Atrial depolarization
Where is the QRS complex and what happens during this?
Ventricular depolarization and atrial repolarization
Where is the T Wave and what happens during this?
Ventricular repolarization
Contraction follows _______.
Depolarization
Relaxation follows ________.
Repolarization
Where is the P-R Interval and what happens during this?
Time required for atrial depolarization and contraction
Where is the P-R Segment and what happens during this?
Atrial contraction
Where is the Q-T Interval and what happens during this?
The combined time required for ventricular depolarization and repolarization
Where is the S-T Segment and what happens during this?
Ventricular contraction
Where is the T-P Segment and what happens during this?
Marks the end of ventricular repolarization and beginning of next cardiac cycle
What is the effects of exercise via the T-P segment?
The segment is shorter so less time between cardiac cycles
What is the effects of exercise via the R-R Interval?
Less time between QRS complexes
systole =
contraction
diastole =
relaxation
What causes heart sounds?
Pressure changes resulting in valves opening and closing
What causes the S1 “lub” sound?
AV valves closing (tricuspid and bicuspid)
What causes the S2 “dub” sound?
Semilunar valves closing
What is S3?
Not a primary heart sound, can hear it in children
Where does the first heart sound occur?
After the QRS complex
Where does the second heart sound occur?
After the T wave
True or False: The SA Node is the natural pacemaker of the heart.
True
What does the AV node do?
Creates a short delay in conduction
What does the Bundle of His do?
Conducts action potentials through the interventricular septum
What does the Purkinje fibers do?
Conducts electrical signals directly to contractile myocytes in ventricle
Note 
Flashcard (137)