reflex contraction

例句：

1. 1. The muscle reflexively contracts when it senses a stimulus.
   肌肉在感受到刺激时会本能地收缩。
2. 2. The heart's reflexivecontraction is essential for maintaining blood pressure.
   心脏的反射性收缩对于维持血压至关重要。
3. 3. During the fight or flight response,the body undergoes reflexive contractions of the diaphragmand other muscles.
   在战斗或逃跑反应中，身体会经历肺和其它肌肉的反射性收缩。