HSS 396 FINAL EXAM QUESTIONS WITH ANSWERS
100% CORRECT
Depolarization - ANSWER when gated ion channels open, positively charged cations
flow into myocardial cell
*generates AP
Repolarization - ANSWER Repolarization: follows depolarization; fast acting K+
channels open; allows K+ efflux ~ AP back to baseline
upward deflection of EKG - ANSWER current moving toward electrode
downward deflection of EKG - ANSWER current moving away from electrode
Sinoatrial (AV) node - ANSWER *The Conduction System of the Heart*
- electrical signal originates here (60-100bpm)
o Signal depolarizes atria and passes to AV node
atrioventricular (AV) node - ANSWER a node of specialized heart muscle located in the
septal wall of the right atrium; receives impulses from the sinoatrial node and transmits
them to the atrioventricular bundle
Bundle of His (AV bundle) - ANSWER located next to the AV node; provides the transfer
of the electrical impulse from the atria to the ventricles
Right & left bundle branches - ANSWER Two pathways in interventricular septum
, Carry impulses toward apex of heart
purkinje fibers - ANSWER specialized conductive fibers located within the walls of the
ventricles
- carry signal to myocardium
-depolarizes @ 30bpm
P wave - ANSWER atrial depolarization
-small, rounded wave
QRS complex - ANSWER ventricular depolarization and atrial repolarization
- <.12 seconds in duration
T wave - ANSWER ventricular repolarization
-small, rounded wave
PR segment - ANSWER represents brief pause as electrical signal is delayed @ AV node
for .12 seconds
- Measured from beginning of P wave to beginning of QRS complex
- <.20 seconds
ST segment - ANSWER represents time between ventricular depolarization and
repolarization
- Measured from end of S wave to beginning of T wave
100% CORRECT
Depolarization - ANSWER when gated ion channels open, positively charged cations
flow into myocardial cell
*generates AP
Repolarization - ANSWER Repolarization: follows depolarization; fast acting K+
channels open; allows K+ efflux ~ AP back to baseline
upward deflection of EKG - ANSWER current moving toward electrode
downward deflection of EKG - ANSWER current moving away from electrode
Sinoatrial (AV) node - ANSWER *The Conduction System of the Heart*
- electrical signal originates here (60-100bpm)
o Signal depolarizes atria and passes to AV node
atrioventricular (AV) node - ANSWER a node of specialized heart muscle located in the
septal wall of the right atrium; receives impulses from the sinoatrial node and transmits
them to the atrioventricular bundle
Bundle of His (AV bundle) - ANSWER located next to the AV node; provides the transfer
of the electrical impulse from the atria to the ventricles
Right & left bundle branches - ANSWER Two pathways in interventricular septum
, Carry impulses toward apex of heart
purkinje fibers - ANSWER specialized conductive fibers located within the walls of the
ventricles
- carry signal to myocardium
-depolarizes @ 30bpm
P wave - ANSWER atrial depolarization
-small, rounded wave
QRS complex - ANSWER ventricular depolarization and atrial repolarization
- <.12 seconds in duration
T wave - ANSWER ventricular repolarization
-small, rounded wave
PR segment - ANSWER represents brief pause as electrical signal is delayed @ AV node
for .12 seconds
- Measured from beginning of P wave to beginning of QRS complex
- <.20 seconds
ST segment - ANSWER represents time between ventricular depolarization and
repolarization
- Measured from end of S wave to beginning of T wave
