Learn: Cardiac Cycle, Cardiac Output and Blood Pressure

Welcome!Building on what you've learned about the heart and blood vessels, this lesson will focus on the cardiac cycle, cardiac output, and blood pressure. These concepts are important for understanding how blood circulates through the body.

What is the Cardiac Cycle?The cardiac cycle refers to the sequence of events that occur during one heartbeat. It includes the contraction (systole) and relaxation (diastole) of the heart chambers. This cycle ensures blood is pumped effectively around the body.

Systole and DiastoleDuring systole, the heart muscles contract to push blood out of the chambers. During diastole, the heart muscles relax to allow the chambers to fill with blood. These phases are crucial for maintaining blood flow.

Cardiac OutputCardiac output is the volume of blood pumped by the heart per minute. It is calculated using the formula: Cardiac Output = Stroke Volume × Heart Rate. Stroke volume is the amount of blood pumped per beat, and heart rate is the number of beats per minute.

Blood PressureBlood pressure is the force exerted by circulating blood on the walls of blood vessels. It is measured in two values: systolic pressure (pressure during heart contraction) and diastolic pressure (pressure during relaxation). Normal blood pressure is typically around 120/80 mmHg.

Factors Affecting Blood PressureBlood pressure can be influenced by factors such as age, stress, physical activity, and health conditions. For example, exercise temporarily increases blood pressure as the heart works harder to pump blood.

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