The outermost fibrous layer is made of connective tissue.

最外层的纤维层由结缔组织组成。

In addition there is a thick muscular layer called the detrusor muscle that helps with bladder contraction during urination and it has fibrous adventitia outer layer.

此外，还有一层较厚的肌肉层，称为逼尿肌，能辅助排尿过程，其外层有纤维外膜。