Learn: Cardiac Cycle, Cardiac Output and Blood Pressure

Welcome!Welcome back! You've already studied the structure and function of the heart and blood vessels. Now we'll build on that knowledge by exploring how the heart works in a cycle, how it generates output, and how this relates to blood pressure.

What is the Cardiac Cycle?The cardiac cycle is the sequence of events that occur in one heartbeat. It involves the contraction and relaxation of the atria and ventricles, ensuring blood is pumped efficiently around the body. The cycle is vital for maintaining circulation and delivering oxygen to tissues.

Phases of the Cardiac CycleThe cardiac cycle has three main phases:Atrial systole: The atria contract, pushing blood into the ventricles.Ventricular systole: The ventricles contract, forcing blood into the arteries.Diastole: The heart relaxes, and blood flows into the atria and ventricles.

What is Cardiac Output?Cardiac output is the volume of blood pumped by the heart per minute. It is calculated using the formula:Cardiac Output = Heart Rate × Stroke VolumeThis is important because it reflects how effectively the heart is delivering blood to the body.

How is Blood Pressure Generated?Blood pressure is the force exerted by blood against the walls of the blood vessels. It is created by the pumping action of the heart and the resistance of the blood vessels. It is measured in two values:Systolic pressure: Pressure during ventricular contraction.Diastolic pressure: Pressure during relaxation.

Review Time!Great work! You've learned about the cardiac cycle, cardiac output, and blood pressure. Let's test your understanding with a few final questions.