Lub Dub Sounds Systole Diastole -

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 .

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.' lub dub sounds systole diastole

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