Series of events that constitute a complete heartbeat Cardiac Cycle: Series of events that constitute a complete heartbeat
Cardiac Cycle Explained Khan Academy https://www.youtube.com/watch?v=y5maHDAkzUs
Cardiac Cycle Diagram
Heart Sounds “Lubb” = ventricular contraction; A-V valves close “Dupp” = ventricular relaxation; pulmonary and aortic valves close
Events Atria relax and blood flows in Chambers fill which increases pressure inside causing A-V valves to open Blood flows into ventricles (70-80% of entering blood)
Events, Cont’d Atrial walls contract (atrial systole) which pumps the remaining 20-30% of blood into the ventricles Atrial walls relax (atrial diastole)
Events, Cont’d Ventricles contract (ventricular systole); A-V valves close and blood is pumped out Ventricles relax (ventricular diastole); A-V valves open