Heart Pump & Cardiac Cycle
Follow one heartbeat through the four chambers, valves, ECG trace and blood pressure.
Change the heart rate (or press Exercise) and follow one heartbeat: atria squeeze, valves open and close, then the ventricles pump.
About the Heart Pump & Cardiac Cycle
Free heart pump & cardiac cycle. Follow one heartbeat through the four chambers, valves, ECG trace and blood pressure. Drag, change the sliders and see the result live. No sign-up, works on phone and computer. Built for biology, the heart pump & cardiac cycle runs instantly in your browser: change a setting or drag an object and the result updates at once, so you learn by trying things out rather than only reading about them.
Follow one heartbeat through the four chambers, valves, ECG trace and blood pressure. Use it to explore biology ideas at your own pace, then check what you found against the key ideas further down this page.
How to use the Heart Pump & Cardiac Cycle
- Use the controls to change Heart rate, Activity. The simulation reacts instantly.
- Pick an option such as Resting, Walking, Exercise to switch modes or load an example.
- Press "Pause" to start, reset or change what is happening.
- Where you see a glowing handle, object, weight or atom, drag it with your mouse or finger. Everything responds in real time.
- Watch the readouts and graphs update as you experiment, and compare what you see with the key ideas below.
Things to try
- Compare resting and exercise heart rates.
- Watch when each valve opens.
- Find the moment of the QRS spike on the ECG.
Key ideas you can learn
- The atria contract first, then the ventricles.
- Valves make sure blood only flows one way.
- Cardiac output = heart rate × stroke volume.
- Blue blood is low in oxygen; red blood is high in oxygen.
Where this is used in the real world
Doctors read ECGs to spot arrhythmias and heart attacks, and athletes track heart rate to train safely.
Who is this simulation for?
Biology students and teachers who want to explore living systems, populations and genetics interactively and safely.
For teachers: project it on the board, let students predict what will happen, then run it together. For students: change one thing at a time and write down what changes.
Frequently asked questions
What are the phases of the cardiac cycle?
Atrial systole, ventricular systole and diastole (relaxation and refilling).
What is cardiac output?
The volume of blood pumped per minute: heart rate multiplied by the stroke volume.
Is the Heart Pump & Cardiac Cycle free to use?
Yes. It is completely free, with no signup, no download and no ads inside the simulation. It runs in your web browser.
Does the Heart Pump & Cardiac Cycle work on a phone or tablet?
Yes. It uses touch as well as the mouse, so you can drag objects with your finger. A larger screen makes the controls easier to see.