Cardiac Cycle Quiz AS level (CIE)

Which of the following occurs during atrial systole?

• Both atria contract, and blood is forced into the ventricles.

• The ventricles contract, and blood is ejected into the arteries.

• The atrioventricular valves close to prevent backflow into the atria.

• The semilunar valves open to allow blood to flow into the arteries.

What prevents backflow of blood into the left atrium during ventricular systole?

• Semilunar valves

• Atrioventricular valves

• The thick walls of the left ventricle

• The pulmonary valve

During diastole, which of the following events occurs?

• The ventricles contract and the semilunar valves open.

• The atria fill with blood, and the atrioventricular valves open.

• The semilunar valves close, and the ventricles fill with blood from the arteries.

• The atria contract to force blood into the ventricles.

Which part of the heart generates the electrical impulse that starts the cardiac cycle?

• Purkyne tissue

• Atrioventricular (AV) node

• Sinoatrial (SA) node

• Bundle of His

What is the correct sequence of events in the cardiac cycle?

• Atrial systole → Diastole → Ventricular Systole

• Ventricular systole → Atrial systole → Diastole

• Diastole → Atrial systole → Ventricular systole

• Atrial systole → Ventricular systole → Diastole

Which valve prevents backflow of blood into the right ventricle?

• Tricuspid valve

• Bicuspid valve

• Pulmonary valve

• Aortic valve

What is the function of the atrioventricular node (AV node) in the cardiac cycle?

• To generate the electrical impulse that initiates heart contraction

• To delay the electrical impulse, allowing time for ventricular filling

• To transmit the electrical impulse directly to the Purkyne tissue

• To close the semilunar valves during diastole

Which of the following correctly describes the pressure changes in the left ventricle during ventricular systole?

• Pressure decreases rapidly as the ventricles relax.

• Pressure remains constant throughout the cardiac cycle.

• Pressure increases and becomes lower than in the aorta.

• Pressure increases and becomes higher than in the left atrium.

What happens when the semilunar valves close during the cardiac cycle?

• Blood is prevented from flowing back into the ventricles.

• Blood flows from the atria into the ventricles.

• The ventricles contract to force blood into the arteries.

• The atrioventricular valves open to allow blood flow.

What causes the 'lub' and 'dub' sounds of the heartbeat?

• Contraction of the atria and ventricles

• Opening and closing of the semilunar valves

• Closing of the atrioventricular valves and semilunar valves

• Blood flowing into the ventricles and arteries