Cardiac cycle

• Cardiac diastole

  Relaxation of cardiac muscle

  atria relax before ventrical
• cardiac systole

  Contraction of cardiac muscle

  atria contract before ventrical
• Phases of cardiac cycle

  
• diastole

  Atria then ventricales relax and draw blood into the atria

  Pressure in the atria increase, opening AV valves

  Blood enters passively, SL valves open 0.4s
• Atrial systole 


  Atria contract, forcing any remaining blood into the ventricals

  0.1s
• Ventricular systole

  Ventricals contract, pressure increases

  AV valves close

  SL valves forced open as blood is ejected from ventricals to pulmonary artery ano aorta

  0.3s