MICROANATOMY

Detailed explanation-1: -The primary function of the detrusor muscle is to contract during urination to push the urine out of the bladder and into the urethra. The detrusor muscle will relax to allow the storage of urine in the urinary bladder.

Detailed explanation-2: -As your bladder fills, nerve signals sent to your brain eventually trigger the need to urinate. When you urinate, these nerve signals coordinate the relaxation of the pelvic floor muscles and the muscles of the urethra (urinary sphincter muscles). The muscles of the bladder tighten (contract), pushing the urine out.