Learn: Cardiac Cycle, Cardiac Output and Blood Pressure

Welcome!Building on what you've already learned about the heart and blood vessels, today we'll dive into how the heart pumps blood efficiently during the cardiac cycle and explore concepts like cardiac output and blood pressure.

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

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 arteries.Diastole: Both atria and ventricles relax, allowing them to fill with blood.Valves prevent backflow during these phases.

What is Cardiac Output?Cardiac output is the volume of blood pumped by the heart per minute. It depends on two factors:Heart rate: The number of beats per minute.Stroke volume: The amount of blood pumped per beat.Formula: Cardiac Output = Heart Rate × Stroke Volume.

Blood PressureBlood pressure is the force exerted by blood on the walls of blood vessels. It's measured in two values:Systolic pressure: Pressure during ventricular contraction.Diastolic pressure: Pressure during relaxation.Normal blood pressure is approximately 120/80 mmHg.

Factors Affecting Blood PressureBlood pressure can be influenced by:Age: Older people often have higher blood pressure.Exercise: Raises blood pressure temporarily.Diet: High salt intake can increase blood pressure.Stress: Can raise blood pressure.

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.

Well done!You've completed the lesson on the cardiac cycle, cardiac output, and blood pressure. Keep reviewing and practising to master these concepts!