looking for a short detailed answer. cheers.
2006-11-12 05:19:08 · 8 answers · asked by Anonymous in Science & Mathematics ➔ Biology
The first heart sound is due to the closing of the atrioventrical valves (i.e. the mitral and tricuspid valves). It is due to the leaflets of the valves snapping together under pressure, just before the ventricles contract.
This is generally louder than the closing of the pulmonary and aortic valves, which cause the dup sound.
2006-11-12 05:26:10 · answer #1 · answered by the last ninja 6 · 2⤊ 0⤋
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The 'lub- dub' is the sound of your heart valves opening and closing. (S1 or 'lub' ) is caused by closing of the mitral and tricuspid valve as the ventricles begin to contract and pump blood into the aorta +pulmonary artery. The second sound (S2 or 'dub') is caused when the ventricles begin to relax and allow the aortic and the pulmonary valves to close.
2016-04-04 23:44:06 · answer #2 · answered by Anonymous · 0⤊ 0⤋
What Causes Heart Sounds
2016-11-07 05:04:08 · answer #3 · answered by als 4 · 0⤊ 0⤋
Normal heart sounds are caused by the closing of valves within the heart after blood has flown through them. The usual lub-dub is caused by the closing of the atrioventricular valves (mitral and tricuspid) and semilunar valves (aortic and pulmonary) respectively.
2016-03-16 03:51:33 · answer #4 · answered by ? 4 · 0⤊ 0⤋
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RE:
What causes the first heart sound or the 'lub'?
looking for a short detailed answer. cheers.
2015-08-16 18:55:46 · answer #5 · answered by Anonymous · 0⤊ 0⤋
LUB is first. It is the sound of the Atrioventricular valves closing.
Tricuspic (Rt ventricle) and Bicuspid (Mitral) Valve (Lt ventricle)
The second sound "DUB" is the sound of the SEMILUNAR valves closing.
Pulmonary valve and the aortic valve.
They prevent the backflow of blood into the heart during the contraction of the heart muscle.
2006-11-12 05:26:02 · answer #6 · answered by konstipashen 5 · 1⤊ 0⤋
The lub sound comes from the atria-ventricular valves closing in the heart.
2006-11-12 05:27:15 · answer #7 · answered by jjewel 3 · 0⤊ 0⤋
the beating sound is caused by the valves to the heart opening and closing. if memory serves me correctly the first beat is a valve opening, while the heart beats your blood through your system. check wikipedia.org and look up heart just to be sure.
2006-11-12 05:28:34 · answer #8 · answered by Mr. 210 7 · 0⤊ 0⤋
Lub is first.
2006-11-12 05:20:18 · answer #9 · answered by bor_rabnud 6 · 0⤊ 0⤋