detrusor urinae of bladder

例句：

1. 1.The detrusor muscle is responsible for contracting the bladder to expel urine.
   括约肌负责收缩膀胱以排出尿液。
2. 2.The detrusor muscle is also involved in urination.
   括约肌还参与排尿过程。
3. 3.The detrusor muscle is a crucial part of the bladder's function.
   括约肌是膀胱功能的关键部分。