Structure of the heart
Human heart and circulation · Biology
Beating heart
Interactive 3DA stylized heart pulsing at the rate you set, with its key chambers labelled.
Controls
Drag the sliders or type a value — the simulation updates live.
bpm
40bpm120bpm
Study notes
Place your hand on your chest: the 'lub-dub' you feel is the heart's valves slamming shut — 'lub' when atrioventricular valves close as ventricles contract, 'dub' when semilunar valves close. A heart murmur — an extra whooshing sound — means a valve leaks, which doctors detect with a stethoscope.