心音是心脏跳动时发出的声音。心脏跳动一次,叫-个心动周期,包括心房和心室各收缩一次。心音是由心脏瓣膜关闭和心脏收缩及血流加速或减速引起的振动所产生。每一心动周期平均为0.8秒,其中收缩期时间短,舒张期的时间长,这是非常合理而巧妙的劳逸安排。因为心脏收缩时为工作,舒张时为休息,工作时间短而休息时间长,保证为收缩时有充沛的力量搏出更多的血液,以供给全身的需要。人们都以按脉来判断心脏 Heart sound is the sound of heart beating. Heart beat once, called - a cardiac cycle, including contraction of the atria and ventricles. Heart sounds are caused by heart valve closure and contraction of the heart and the acceleration or deceleration of blood flow. Each heart cycle average of 0.8 seconds, of which systolic time is short, diastolic time is long, this is a very reasonable and clever work arrangements. Because the contraction of the heart for work, when diastolic relaxation, short working hours and rest for a long time, to ensure that there is plenty of power when contracting stroke more blood to supply the body needs. People press the pulse to determine the heart