What Produces The — Lub Dub Heart Sounds

The classic Lub-Dub is actually the sound of doors slamming shut —the echo of turbulence, vibrations, and sudden hydraulic jams. Here’s the surprising physics and physiology behind the world’s most famous two-note song. The heart is a four-chambered muscular marvel: two upper chambers (atria) and two lower chambers (ventricles). When you feel your pulse, you are feeling the pressure wave of the left ventricle squeezing blood out to your body.

The "Lub" is the sound of the exit doors closing just as the heart tries to pump. Part 3: The "Dub" (The Escape Hatch Snap) After the "Lub," the ventricles continue to squeeze. They blast blood out through two other doors: the pulmonary valve (to the lungs) and the aortic valve (to the body). For a brief moment, the heart is emptying. what produces the lub dub heart sounds

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. The classic Lub-Dub is actually the sound of

And as long as you hear Lub...Dub...pause , you know the show is still going. When you feel your pulse, you are feeling

Place your hand on the left side of your chest. Feel that? Thump-thump... thump-thump.

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.