In anatomy, the urinary bladder (roughly translated from vesicle)'s a solid, muscular, and distensible (or elastic) organ that sits on the pelvic floor. It's the organ that collects urine excreted by the kidneys prior to disposal by urination. Urine enters the bladder via the ureters and exits via the urethra. Embryologically, the Bladder's derived from the Urogenital sinus and, it's initially continuous with the allantois. In males, the base of the bladder lies between the rectum and the pubi… (More on Detrusor)