英语翻译1.Closure of the valves of the heart produces mechanical

英语翻译
1.Closure of the valves of the heart produces mechanical vibrations which are audible at the chest wall as the heart sounds.The first heart sound is caused by the closure of the atrioventricular valves and so marks the beginning of ventricular systole.The second heart sound is caused by closure of the aortic and pulmonary valves.Clinically,ventricular systole is regarded as the period between the first and second heart sounds,while diastole is the time between the second heart sound and the first heart sound of the next cycle.It should be noted that valve opening makes no detectable sound.
2.Venous return rises as a result of compression of the veins by contracting skeletal muscle and therefore,increases cardiac output.
3.Arterial pressure acts as the driving force for blood flow through the tissues of the body.If blood pressure drops,perfusion (灌注)of organ may fail,and this becomes an acute,life-threatening situation if blood flow through the brain or heart is impaired.
4.The function of thiamine in the body is to form the active part of “coenzyme” of certain enzymes involved in the metabolism of carbohydrates,particularly of pyruvic acid(丙酮酸).When a thiamine deficiency interferes with carbohydrate metabolism,a number of characteristic symptoms appear:in mild deficiences there is fatigue,loss of appetite,weakness and muscular cramps; in more marked deficiencies these symptoms are accentuated,and there is also a painful degeneration of the nerves and a secondary wasting of the muscles resulting in paralysis.This condition is called beriberi.
5.Of these,one-third do not survive the operation,while of those who do recover more than half die from recurrence of the disease or the associated causes within a few years.

1 .关闭阀门心脏机械振动产生的声响在胸壁的心音.第一心音的原因是关闭房室瓣膜等标志着心室收缩.第二心音的原因是封闭的主动脉和肺动脉瓣.临床上,心室收缩被视为间的第一和第二心音,而舒张期之间的时间是第二心音第一心音的下一个周期.应当指出的是,阀门开没有探测声音.
2 .静脉回流增加,由于压缩的静脉骨骼肌的收缩,因此,增加心输出量.
3 .动脉压作为动力血流通过组织的机构.如果血压下降,灌注（灌注）的器官可能会失败,并且这已成为一个严重的,危及生命的情况,如果血液流经脑部或心脏受损.
4 .维生素B1的作用是在人体中形成积极参与的“辅酶”的某些酶参与代谢的碳水化合物,特别是丙酮酸（丙酮酸） .当维生素B1缺乏症干扰糖代谢,一些特征出现症状：轻度deficiences有疲劳,食欲不振,虚弱和肌肉痉挛;更加明显的缺陷在这些症状加重,而且也有一个痛苦的豆状核变性的神经和次要浪费造成肌肉麻痹.这种情况被称为脚气病.
5 .其中,有三分之一没有生存的运作,而这些谁做收回一半以上死于复发的疾病或相关的原因在几年之内.