What Makes The Lub Dub Sound: In The Heart |verified|

It is the soundtrack to our lives, beating approximately 100,000 times a day. But have you ever stopped to wonder what is actually making that noise? Is it the muscle squeezing? Is it blood sloshing around?

This creates the sharper, shorter dub , technically known as . what makes the lub dub sound in the heart

: After the ventricles finish pumping blood into the aorta and pulmonary artery, the pressure in those large vessels becomes higher than the pressure inside the now-relaxing ventricles. Blood tries to flow back into the heart, which catches the leaflets of the aortic and pulmonary valves and snaps them shut. Why Valve Health Matters It is the soundtrack to our lives, beating

If you’ve ever placed your hand over your chest or listened to a friend’s heartbeat through a stethoscope, you’ve heard it: the steady, rhythmic lub-dub, lub-dub . Is it blood sloshing around

The standard “lub = AV valves close, dub = semilunar valves close” is . It’s a classic answer that requires no correction — only possible expansion for depth.

If you listen closely, there is a rhythm to the sound: Lub-Dub... (pause)... Lub-Dub.

Here's the sequence of events that produces the lub-dub sound: