circular muscle layer

例句：

1. 1. The circular muscle layeris responsible for the movement of the heart.
   环形肌肉层负责心脏的运动。
2. 2. The circular musclelayer helps to support the body'sweight.
   环形肌肉层有助于支撑身体的重量。
3. 3. Thecircular muscle layer is a crucial part ofthe digestive system.
   环形肌肉层是消化系统的重要组成部分。