MCB Module 19 Cardiac Cycle

Filling phase

The phase during diastole when the atria and ventricles passively fill with blood as the AV valves are open.

Isovolumetric contraction

The first part of systole where the ventricles contract, increasing pressure, causing AV valves to close, without a change in blood volume.

Ventricular ejection

The second part of systole where pressure in the ventricles increases enough to open semilunar valves, allowing blood to flow into the arteries.

Isovolumetric relaxation

The phase when the ventricles relax and pressure drops below arterial pressure, closing the semilunar valves, with no volume change.

End-diastolic volume (EDV)

The volume of blood in the ventricle at the end of diastole, representing maximum ventricular volume.

End-systolic volume (ESV)

The volume of blood in the ventricle at the end of systole, representing minimum ventricular volume.

Stroke volume (SV)

The amount of blood ejected from the heart during one beat, calculated as EDV - ESV.

Diastolic pressure

The decreased pressure in the aorta during diastole as blood flows through the vessels.

Systolic pressure (SP)

The increase in blood pressure in the aorta when the semilunar valves open and blood enters.