membranous part的用法和样例：
例句
- Active continence is achieved by voluntary contraction of the levator ani musculature, which surrounds the apex of the prostate and membranous urethra.
前列腺尖部和膜部周围的提肛肌的主动收缩可以导致主动性控尿。 - The external sphincter, at the leel of the membranous urethra, is often depicted as a "sandwich" of muscles in the horizontal plane.
外括约肌，位于尿道膜部水平，常被描述为水平平面上的三明治样肌肉。
