The urinary bladder has an average capacity to store half a liter of liquid, but can contain up to two and three liters in extreme cases.
We all go to the bathroom several times a day, although we can not always do it at the same time when we feel that need, and we have no choice but to put up with it. But how much can we bear the urge to urinate?
It is estimated that a medium urinary bladder has a natural capacity that allows it to store about 500-600 milliliters of fluid. Although this capacity may increase in cases of extreme need, and the bladder expands allowing to accumulate up to two or three liters. Amount that is considered its extreme limit of storage.
The usual is to start feeling like urinating when you have accumulated between 250 and 350 milliliters of fluid. From that moment, the retention of the liquid in its interior is possible thanks to the action of two muscles: the sphincter, that contracts to avoid the exit of the urine, and the otrusor. In principle, the action of these muscles is regulated unconsciously but, as the amount of stored fluid increases, it is necessary to make a greater effort to favor its retention.
Finally, when you finally want to release it, or the retention capacity has reached its maximum, the sphincter relaxes and the otrusor muscle contracts, a combined action that allows the exit of the urine.
The time it takes for the bladder to fill with urine depends a lot on the number of times it is drunk. The usual thing is that in a couple of hours you reach that amount of 250 or 350 milliliters, from which our body begins to send us signs that it is time to go to the bathroom.
Reference: http://www.businessinsider.com/how-long-can-you-go-without-peeing-2013-9
