1. The problem statement, all variables and given/known data I was given the hard task of matematically modeling the human urinary system. I have to keep into account all the things going on. We CAN NOT model the bladder as being a sphere. So that is the main problem. It has the shape of an onion more or less. And it reduces and increases its volume depending on the amount of urine present. The approx. volume of the bladder is 400 cm3. Basically what I'm looking for are ideas on how to model the bladder as a sistem, as the farthest we've gone is modeling spherical and cilindrical systems. Any help is DEEPLY appreciated.