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Cardiac Physiology
Lab Study Guide
Term | Definition |
---|---|
lubb | -come first -closure of AV valves |
dupp | -comes second -closure of SL valves |
when ventricles contract AV valves open or close? | close |
when atria contract AV valves open or close? | open |
when ventricles relax AV valves open or close? | open |
when atria relax AV valves open or close? | close |
path of electrical activity | - SA node -atrial contraction -AV node -AV bundle -R/L bundle branches -Purkinje fibers (conduction myofibrils) -ventricular contraction |
systole | contraction |
diastole | relaxation |
p wave | atrial depolarization (causes systole) |
QRS complex | ventricular depolarization (causes systole) |
when do the atria repolarize? | during the QRS complex but the large electrical activity of the ventricular depolarization masks atria repolarization |
t wave | ventricular repolarization (causes diastole) |
significance of PQ segment | -start of atrial depolarization to start of ventricular depolarization -measures time it takes to get from AV node to ventricles |
significance of PR interval | -time from atrial depolarization to beginning of ventricular depolarization -time to transmit action potential through entire conduction system -reflects whether impulse conduction from atria to ventricles is normal |
significance of ST segment | -normally remains isoelectric (no electrical activity) -interval between ventricular depolarization and repolarization |
significance of QT interval | includes all electrical events from ventricular repolarization to depolarization |
cardiac cycle | complete cycle of contraction and relaxation of all four chambers of the heart |
R-R interval | heart rate |
calculating HR given cardiac cycle | -HR = 60/CC -answer in BPM |
calculating cardiac cycle given HR | -CC = 60/HR -answer in seconds |
wave | electrical changes with depolarization and repolarization |
segment (on line) | between waves |
interval | wave and segment |