Cardiac Cycle Flashcards
What id the cardiac cycle a sequence of
pressure and volume chnages that take place during cardiac activity
what are the mechial events of the cardiac cycle brought about by
rhymtic chnages in cardiac electrical activity
what are the alternate peroids
Stystole - contraction and emptrying
Diatole - relaxation and filling
What are the names of the valve
tricuspid and bicuspid valves
Mechanism of valve action opened
when pressure is greater behind the valve it opens
Mechanism of valve action clsoed
when pressure is greater in front of the valve it closes
does not open the opposite direction
what is a ECG
record of the overall spread of electrical activity through the heart
P wave
atrial depoalrisation
PR segment
AV nodal delay
QRS segment
ventricular depolarisation (atria repolarisation simulteaneouly)
ST segment
time during which ventricles are contracting and emptying
T wave
ventricular repolarisation
TP
time during ventricles are relaxing and filling
What are the 5 major phases of the cardiac cycle
Filling peroid
Atrial contraction
isovloumteric ventricular contraction
Ejection
Isovolumetric ventricualr relaxation
What are the heart sounds
1st coincides with the beginning of systoleproduced by closure of the AV valves
2nd begins with the onset of diastole- closure of the aortic and pulmonary (semilunar)valves
