is a small upward deflection on the ECG it represents atrial depolarization which spreads from the SA nodes through contractile fibers in both atria
begins as downward deflection, continues as a large upright, triangular wave and ends as a downward wave. It represents rapid ventricular depolarization, as the action potential spreads through ventricular contractile fibers
a dome shaped upward deflection. It indicates ventricular re polarization and occurs just as the ventricles are starting to relax.
refers to the phase of contraction. the atria and ventricles depolarize and then contract at different times.
the phase of relaxation
includes all the events associated with on heartbeat. Thus it consists of a systole and diastole of the atria plus systole and diastole of the ventricles
the atria are contracting the same time the ventricles are relaxing
the ventricles are contracting the same time the atria are relaxing
during this interval cardiac muscle fibers are contracting exerting force but are not yet shortened. Both semilunar valves and AV valves are closed
the period when the SL valves are open
end-systolic volume (ESV)
the volume remaining in each ventricle at the end of systole
the volume ejected per beat from each ventricle, equals end-diastolic volume minus end systolic volume
the atria and ventricles are both relaxed.
caused by ventricular repolarization as the ventricles relax pressure within the chambers falls
after the sl valves close there is a brief interval when ventricular blood volume does not change because all four valves are closed.
as the ventricles continue to relax. The pressure falls quickly. When ventricular pressure falls below atrial pressure, the av valves open and this begins
during each cardiac cycle there are four of these. but in a normal heart only the first and second heart sounds are loud enough to hear
the first sound. Is louder and a bit longer than the second sound. it is caused by blood turbulence associated with closure of the AV valves soon after ventricular systole begins
the second heart sound which is shorter and not as loud as the first. it is caused by blood turbulence associated with closure of the SL valves at the beginning of the ventricular diastole
is an abnormal sound consisting of a clicking rushing or gurgling sound that either is hear before, between or after the normal heart sounds or may mask the normal heart sounds.