肌肉收缩时,长度缩短的收缩称为向心收缩(concentric contraction),又称为缩短收缩。向心收缩时肌肉长度缩短、起止点相互靠近,因而引起身体运动。而且,肌肉张力增加出现在前,长度缩短发生在后。 向心收缩是骨骼肌主动用力的收缩形式。肌肉向心收缩时,是做功的,其数值为负荷重量与负荷移动距离的乘积。 向心收缩时可以是等张收缩也可以是等动收缩。
相同速度下,患侧和健侧股四头肌和腘绳肌离心收缩肌力明显大于向心收缩;
The eccentric contraction of both sides′ quadriceps and hamstring produced significantly higher torques than concentric contraction did in same speed.
所以当你的心房收缩时,夹在心房和心室之间的阀门就打开了,然后每个心房里的血液通过各自的阀门流向心室。
So when the atria contract, the valves sandwiched between the atria and the ventricles open, and the blood in each atrium flows through its respective valve down into a ventricle.
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