Cardiac Cycle-Hard Quiz

Cardiac Cycle Phases

• Atrial contraction occurs during the atrial systole phase, where the atria contract and push blood out of the atria and into the ventricles.
• Isovolumetric ventricular contraction phase is characterized by ventricular contraction without any change in ventricular volume.

Ventricular Contraction and Ejection

• Ejection occurs during the ventricular ejection phase, where the ventricles contract and pump blood out of the heart.
• The purpose of isovolumetric ventricular relaxation is to allow the ventricles to relax and prepare for the next cycle of contraction.

Ventricular Filling

• Passive ventricular filling occurs when the ventricles relax and fill with blood from the atria.
• Active ventricular filling occurs when the atria contract and push blood into the ventricles.

Ventricular Systole Initiation

• Ventricular systole is initiated by the electrical signal from the atrioventricular (AV) node.

Isovolumetric Ventricular Contraction Purpose

• The purpose of isovolumetric ventricular contraction is to generate enough pressure to open the semilunar (SL) valves.

Residual Volume

• Residual volume is the volume of blood remaining in the ventricles after contraction.

SL Valves Closure

• The SL valves close due to the increased pressure in the aorta and pulmonary arteries, which exceeds the pressure in the ventricles.

Ventricular Filling Types

• Ventricular filling can be either passive or active, depending on the phase of the cardiac cycle.