Eli5: How does our bladder avoid low pressure when we’re peeing?

Question

Eli5: How does our bladder avoid low pressure when we’re peeing?

In: Biology

Answer 1

Define low pressure.

If you mean constant pressure that’s lower than atmospheric, you’d need to seal the bladder and then expand the bladder’s volume — that’s not possible naturally.

The bladder is constantly under higher pressure because it’s a balloon whose walls are slightly pressing against its contents (i.e., yer pee pee liquids). When you pee, the pressure is slowly lowered, but it’s never “low.” The size of the bladder deceases as the volume of the bladder contents decreases, so that regulates pressure.