The Cardiac Cycle is SO EASY! Stop Making it Hard!

Leslie Samuel from Interactive Biology explains the cardiac cycle, covering the flow of blood through the heart, the role of the electrocardiogram (ECG), and the phases of atrial and ventricular systole. The video breaks down complex concepts like isovolumetric contraction and ejection, and discusses the sounds of the heartbeat. The tutorial aims to simplify the understanding of the cardiac cycle, making it accessible and engaging.

What is the primary function of the atria during the cardiac cycle?

• To pump blood into the lungs

• To receive blood from the body and lungs

• To contract and push blood into the ventricles

• To maintain constant blood pressure

What does the P wave on an ECG represent?

• Ventricular depolarization

• Atrial depolarization

• Ventricular repolarization

• Atrial repolarization

During atrial systole, what happens to the ventricular volume?

• It decreases

• It remains the same

• It fluctuates

• It increases

What does the QRS complex indicate in the cardiac cycle?

• Atrial contraction

• Ventricular contraction

• Atrial relaxation

• Ventricular relaxation

What is the significance of isovolumetric contraction?

• The volume of blood in the ventricles increases

• The volume of blood in the ventricles decreases

• The volume of blood in the ventricles remains constant

• The volume of blood in the atria remains constant

What does the T wave on an ECG signify?

• Atrial depolarization

• Ventricular depolarization

• Ventricular repolarization

• Atrial repolarization

What causes the 'Lub Dub' sounds of the heartbeat?

• Opening of the atrioventricular valves

• Closing of the atrioventricular and semilunar valves

• Opening of the semilunar valves

• Blood flow through the aorta