What Is Lub Dub Sound In Heart Guide

A heartbeat later came the second sound. This was the sharp, higher-pitched "dub." It was the sound of the two Semilunar Valves—the Pulmonary and Aortic—snapping shut. After the ventricles had finished their mighty squeeze and pushed blood out to the lungs and body, they relaxed. For a moment, the blood in the great arteries wanted to rush back into the heart. But the Semilunar Valves caught it like a parachute catching air. Click! They shut with a crisp, brief snap. That was the .

"Why do you make that noise?" she asked the old Mitral Valve. "Doesn't it hurt?" what is lub dub sound in heart

Then came a pause. A quiet, patient silence. A heartbeat later came the second sound

The Mitral Valve chuckled, its two leaflets trembling. "Hurt? No, little one. That 'lub-dub' is our promise. The lub is us—the entry gates—closing to make sure you go down into the ventricle, not back up. The dub is the exit gates closing to make sure you go out to the body, not back in. The silence between us? That's the moment the heart refills with love—and blood—for the next beat." For a moment, the blood in the great