And as long as you hear Lub...Dub...pause , you know the show is still going.
And the tiny gap between the Lub and the Dub? That’s —the actual pumping phase. But again, pumping is silent. So the only reason we hear two distinct noises is because we are listening to the boundaries of the pump: the valves slamming at the start and the valves snapping at the finish. Part 5: The Party Trick (Breathing and Splitting) Here’s where it gets weird enough to impress your friends. If you listen to a child’s heart with a stethoscope and tell them to take a deep breath, the "Dub" suddenly turns into "Du-ub." It splits into two distinct sounds. what produces the lub dub heart sounds
The "Dub" is the sound of the escape hatches closing after the blood has left. Part 4: The Bizarre Physics of the Silent Gap Notice the rhythm: Lub...Dub...pause...Lub...Dub...pause. And as long as you hear Lub
Then comes (S2), marking the end of systole and the beginning of diastole (relaxation). But again, pumping is silent
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.
In fact, your heart is mostly silent during the actual pump.
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.