01 / Location & anatomical relationships
Low in the pelvis, behind the pubic bones.
02 / Structure & organization
Urothelium lines the bladder and accommodates changing volume. The detrusor smooth muscle forms its muscular wall. The trigone is bounded by the two ureteric openings and the internal urethral opening.
03 / Function
When it fills, nerves send messages that you need to urinate.
04 / Mechanism
Its wall stretches as urine arrives and contracts to help empty it. Nerves monitor filling, while muscles around the outlet help hold urine in. Brain signals coordinate when it is time to release it.
Working together: urinary system
Kidneys make urine, ureters carry it to the bladder, and the urethra provides the path out during urination.
Meet this body system →FOR DEEPER STUDY
Connect structure with function
Storage and voiding require coordinated autonomic, somatic and central control. During voiding, detrusor contraction must be matched with relaxation of the outlet mechanisms.
Check your understanding
Locate the bladder in relation to its neighbors. Explain how the structural features described above support its function, then distinguish it from a nearby structure with a different role.
Keep learning
Further reading: NIDDK: Your Kidneys & How They Work.
Continue with OpenStax Anatomy and Physiology for system-level study. This atlas is educational and has not undergone independent medical peer review.