no. it occurs at the beginning of isovolumetric relaxation.
A normal heart beat generally consists of 2 distinct heart sounds, informally termed 'lub' and 'dub'. The first heart sound (lub) occurs at the beginning of the heart contraction (systole) and is the sound of the valves between the atria and ventricles closing. The second heart sound (dub) occurs at the end of the contraction, and is the sound of the valves between the major arteries and the ventricles closing.
The heart of a human, or any creature with a heart, does not literally beat. The beating noise or movement of your heart you can feel especially when you have just done physical activity, is the valves slumming shut in sequence. The first sound is the sound of the atrioventricular valve closing at the beginning of ventricular contraction; the second is the sound of the pulmonary and aortic valves shutting at the end of ventricular contraction.
Most people can hear two heart sounds per cycle - a quiet "lub" and a louder "dub". The "lub" sound is the contraction of the two atria, which results in the ventricles being filled with blood. The "dub" sound is the contraction of the two ventricles, which results in blood being forced into the arterial system. However, a trained physician can hear four sounds - the two described above, and two more that represent the sound of the valves opening back up after the contraction is over.
The first heart sound "lub" is caused by the closing of the mitral and tricuspid valves during the beginning of systole (ventricular contraction). The closure of these valves creates vibrations in the surrounding fluid and tissues, resulting in the characteristic sound.
The "lub" sound of our heartbeat, known as the first heart sound (S1), is primarily caused by the closure of the atrioventricular (AV) valves—the mitral and tricuspid valves—during ventricular contraction (systole). When the ventricles contract, blood is pumped out of the heart, and the sudden closure of these valves creates a distinct sound. This sound is essential for indicating that the heart is properly pumping blood and is part of the normal cardiac cycle.
The second heart sound (S2) occurs after the T wave because it corresponds to the closure of the aortic and pulmonic valves in the heart. The T wave represents ventricular repolarization, which happens after ventricular contraction and ejection of blood through the aortic and pulmonic valves. The closure of these valves generates the S2 sound.
Contraction is the reason that railway tracks sound louder in winter.
No Sound But a Heart was created in 1987.
Sound of My Heart was created in 1989.
No, it is not a conjunction, but it could be a contraction of the phrase "sound is" (the sound's coming from in back). It can also be the possessive form of the noun sound (the sound's tone changed).
First heart sound S1-LUB
The sounds in the heart are caused by the opening and closing of the ventricles. There are two sounds and they are called by the first heart sound (S1) and second heart sound (S2), produced by the closing of the AtrioVentricular valves and semilunar valves respectively.