It is a rhythm so constant we often tune it out, yet it is a symphony of complex engineering happening inside our chests roughly 100,000 times a day. But what exactly is that sound? Is it the heart muscle slapping against itself? Is it the blood rushing through the veins?
If you listen to a healthy adult heart, you hear Lub-Dub... Lub-Dub... lub heart sound
Key Points * The heart tone “lub,” or S1, is caused by the closure of the mitral and tricuspid atrioventricular (AV) valves at the... Medicine LibreTexts Normal heart sounds: Video, Causes, & Meaning - Osmosis Finally, let's move down to between the fifth and sixth rib, so in the left fifth intercostal space, near the midclavicular line. ... Osmosis Normal heart sounds: Video, Causes, & Meaning - Osmosis Finally, let's move down to between the fifth and sixth rib, so in the left fifth intercostal space, near the midclavicular line. ... Osmosis Why Your Heart Says “Lub-Dub” ? Nov 2, 2025 — It is a rhythm so constant we often
The heart is divided into four chambers: two upper atria and two lower ventricles. Separating these chambers are the atrioventricular (AV) valves—the mitral valve on the left and the tricuspid valve on the right. When the ventricles have filled with blood, they begin to contract. This sudden increase in pressure forces the mitral and tricuspid valves to snap shut, preventing blood from flowing backward into the atria. Is it the blood rushing through the veins
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