Unlike in the ureter, the lamina propria occasionally contains a muscularis mucosae, which appears discontinuous and contains a haphazard arrangement of wispy, thin bundles of smooth muscle cells. In some instances, the fibers can become hypertrophic and resemble those of the muscularis propria. Uncommonly, adipocytes can be found in the lamina propria.

The muscularis propria is known as the detrusor muscle; as in the lower ureter, it consists of inner and outer longitudinal fibers with an intervening layer of circumferential fibers. Except in the area of the bladder neck, these layers are typically indistinct, appearing as a meshwork of criss-crossed thick muscle bundles. Interspersed through the muscular layers are blood vessels, lymphatics, nerve fibers, and even adipose tissue.