For most of us, it’s the most reliable metronome we’ll ever own. We call it a heartbeat, but in medical terms, it’s known as the . It’s so familiar that we rarely question it. We assume the sound is simply the heart contracting like a fist squeezing blood.
When they snap shut, they create a higher-pitched, crisper snap than the "Lub." This is the
To stop this backflow, the (pulmonary and aortic) snap shut. Unlike the fleshy AV valves, these look like three tiny crescent moons (hence "semilunar") shaped like a Mercedes-Benz logo. what produces the lub dub heart sounds
And as long as you hear Lub...Dub...pause , you know the show is still going.
In fact, your heart is mostly silent during the actual pump. For most of us, it’s the most reliable
As the ventricles finish squeezing, the pressure inside them drops rapidly. The blood that was just blasted into the arteries (the lungs and body) suddenly wants to rush backward into the heart. It’s like a wave hitting a seawall.
Place your hand on the left side of your chest. Feel that? Thump-thump... thump-thump. We assume the sound is simply the heart
Why the silence between the Dub and the next Lub? That pause is —the heart’s rest and recharge phase. During this silence, the ventricles are relaxing, filling passively with blood from the atria. No valves are snapping shut. It’s the quietest part of the cycle.