Lub Dub Sounds Systole Diastole ((exclusive)) May 2026

Diastole. The chamber expands. Pressure drops. Blood trickles in from the lungs. The aortic valve catches the wave, slamming the gate. This is the sound of receiving .

Tap the sound on to hear your own lub-dub. [Visual: Animation of a beating heart with valves opening/closing] lub dub sounds systole diastole

"The human heart doesn't sing. It knocks. Two knocks per beat. Lub... Dub. Diastole

The marks Diastole . The ventricles relax. But wait—the blood tries to flow backward. Luckily, the pulmonary and aortic valves snap closed to stop it. That snapping echo? That’s your 'Dub.' Blood trickles in from the lungs

The marks Systole . This is the heart's power move. The bottom chambers—the ventricles—squeeze tight. The valves between the upper and lower chambers (the AV valves) slam shut. That slamming door? That’s your 'Lub.'

Let’s break it down: