The Cardiac Cycle

These flashcards cover key concepts and terminology related to the cardiac cycle and cardiac output.

Cardiac Cycle

The series of events during one heartbeat, including atrial and ventricular contractions and relaxations.

Systole

The phase of the cardiac cycle where the heart muscle contracts and pumps blood out of the chambers.

Diastole

The phase of the cardiac cycle where the heart muscle relaxes and the chambers fill with blood.

Cardiac Output (CO)

The amount of blood pumped out by each ventricle in one minute, calculated as HR x SV.

Stroke Volume (SV)

The volume of blood ejected from each ventricle during systole.

End Diastolic Volume (EDV)

The volume of blood in each ventricle at the end of ventricular diastole.

End Systolic Volume (ESV)

The volume of blood remaining in each ventricle after systole.

Preload

The degree of stretch of the heart muscle at the end of diastole, primarily affected by the volume of venous return.

Afterload

The resistance the ventricles must overcome to eject blood, determined by arterial pressure.

Frank-Starling Mechanism

The principle that the force of ventricular contraction increases with greater degrees of stretch of the cardiac muscle.