When the bladder fills with urine, sensory nerves send impulses to the brain telling it the bladder is full. The nerves connect with other nerves in the spinal cord to relay this information. In turn, the brain sends impulses back to the bladder instructing it to empty its contents.
Review Date 7/1/2023
Updated by: Kelly L. Stratton, MD, FACS, Associate Professor, Department of Urology, University of Oklahoma Health Sciences Center, Oklahoma City, OK. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.