Class 11 Zoology simulations · Body Fluids and Circulation

The cardiac cycle

Watch the heart’s chambers contract and relax in sequence and hear when the valves close (lub, dub).

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What to notice

At 72 beats per minute one cycle lasts about 0.8 s (0.83 s): atrial systole 0.1 s, ventricular systole 0.3 s, joint diastole 0.4 s.

Key relation

Cardiac output = stroke volume × heart rate ≈ 70 mL × 72 = ~5 L/min

Try this

Raise the heart rate. Which phase gets shorter?

What you can change

• Heart rate: 50 to 180 beats/min
• Stroke volume: 50 to 120 mL

More in Body Fluids and Circulation

• Blood groups and transfusion
• Double circulation
• Electrocardiogram (ECG)

See all Class 11 Zoology simulations or every Physica simulation.