OK, here's the scoop! I know the ureters have back flow valves so the urine does not back up into the kidneys. And I think they have some muscular action. Forgot a lot of my physiology. I have to plead insanity or senility here. JJ you can set me straight on this. In any event urine flows from the kidneys through the ureters into the bladder, neo or Indian or outside prosthetic device. So, what happens when you are hanging upside down, I used to hang from my feet from tree limbs (stopped doing that last year). So does the urine still get "pushed" into the bladder? I assume there is more to it that gravity feed right? So if you have an outside bag for example, how do you ensure that the urine does flow back to the kidneys? I know, I should probably know this, but just in case there is an electric suction pump in my bladder, I want to know more about it.