So to increase the contraction force and tighten her grip, she can recruit another motor unit.

所以为了增加收缩力，收紧她的握力，她可以招募另一个运动单元。

Same goes for indirect muscle recovery markers, like creatine kinase and muscle voluntary isometric force contraction, where active cooldowns don't seem to change much of these recovery factors.

此结果同样在测量间接肌肉恢复的标志物中成立，例如，肌酸激酶活性和肌肉自发等长收缩力，主动冷身不会对这些恢复因素造成影响。

Oxygenated blood returns to the heart by way of pulmonary veins, which empty into the left atrium. Atrial contractions force blood from the left atrium through the mitral valve, also called bicuspid valve, into the left ventricle.

当心室收缩时，左室内血液经主动脉瓣流入主动脉¬----人体最大的动脉，为全身组织供血。