Author Question: Heart beat (Read 826 times)

Perkypinki

  • Sr. Member
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  • Posts: 339
on: Dec 27, 2014
lub dub sound is produced when AV valves and semilunar valves get closed why no sound is produced when valves of heart open?



Celeste

  • Hero Member
  • Posts: 588
Reply #1 on: Dec 30, 2014
The moment intraventricular pressures exceed the pressure of the aorta and pulmonary artery, the aortic and pulmonic valves open.  Blood ejects into the aorta and the pulmonary artery from the respective left and right ventricles.  This results in a large decrease in ventricular volume and an increase in aortic pressure. At rest approximately 2/3 of the ventricle is ejected.

No heart sounds should occur during this phase as the opening of the valves upon ejection of the blood is silent.  If there is a sound then this may indicate a sign of valve disease or intracardiac shunts.



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