GENITO-URINARY SYSTEM: 3
If there is an obstruction to urine outflow from the bladder, the pressure exerted by the bladder musculature needs to be higher in order to force the urine out. The bladder musculature therefore hypertrophies, with irregular bands of muscle fibre cris-crossing the wall this is called trabeculation.
In this case, the obstruction is due to benign prostatic hyperplasia.