Answer:
The detrusor muscle is the layer of the bladder wall responsible for micturition. The detrusor muscle is a smooth muscle that surrounds the bladder and is responsible for contracting during urination to squeeze urine out of the bladder and into the urethra. The other three layers you mentioned - the adventitia, submucosal layer of connective tissue, and inner layer of epithelium - are not directly involved in the process of micturition.
