A normal healthy human being has to answer nature’s call 4-10 times a day. The need to take a pee break starts when the bladder’s pressure rises, which stretches the bladder wall (made of smooth muscle bands called detrusor). It is filled with adrenergic receptors that are responsible for receiving and sending messages between the nervous system and muscle cell.
While the bladder is stretching, it gets filled with urine via ureters from the kidney to the bladder; messages get sent via a sympathetic nervous system with the help of hypogastric nerve, which controls our urge to pee. At this time, we feel no urge to go to the washroom, and even if you go to the restroom during this time, you have to push your bladder manually with the help of abdominal muscles to pee. The reason for this is that our internal urethral sphincter keeps the things tightly closed.
When the urine count in the bladder is equal to or more than one quarter, that time, the receptors in the detrusor and other receptors around the urethral opening signal back to the sacral region to let our brain know that it’s the time to go to the washroom.
Well, this is how we get to know it’s finally the time to pee and get ourselves relaxed.
Don’t try to hold your pee for too long, because it will be harmful. Whenever you feel and urge to pee, you should go to the toilet. But if you’re on a trip and the driver refuses to stop, and you can’t pee, at that time, you can tell your external urethral sphincter that it’s not a good time, and you can make sure that it stays closed. Well, this thing is not recommended, but in emergencies, you can do this to control your urine flow.