The bladder
Urinary bladder · vesica urinaria
A stretchy muscular bag low in your pelvis that stores urine.
What it does
The bladder sits behind the pubic bone. Its muscular wall stretches as it fills. When it holds a few hundred millilitres, stretch sensors tell your brain you need to go, and when you choose to, the wall contracts while the muscles at its outlet relax.
Surprising fact
A healthy adult bladder can comfortably hold around 400 to 600 millilitres, but the urge to go usually starts when it is less than half full.
Why it matters
The pelvic floor muscles help keep the outlet closed, which is why strengthening them helps people with leaking. Children gain bladder control as these nerve pathways mature.
Nearby
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Sources
Drafted with AI help; awaiting a human fact-check against these sources.
Open in the 3D atlas · Suggest a correction · Not medical advice.
3D models: Z-Anatomy & BodyParts3D (CC BY-SA 4.0 / 2.1 JP). Card text CC BY 4.0.