We've all been there -- you've got to go to the bathroom, but, for one reason or another, you just can't.

Is keeping it in such a bad thing?

When you have to relieve yourself, it feels like everything is the sound of water pouring or a hose spraying water, but you do what you must to make sure you don't let your urine fly until you've reached a toilet.

This video explains how exactly our body pees, with a focus on what the heck takes place in our bladder, which stores up urine the way Minnesota stores lakes (get ready to be introduced to the phrase "urethral sphincter," too).

If you're not so interested in the science (or are ina rush because you have to pee), fast forward to the 3:10 mark. That's where you find out what happens when you hold it in too much. The bottom line: doing so can cause trouble for your body down the road, but for now, don't worry about bypassing the bathroom so you can see the end of the that movie that has you riveted. Just make sure you race to the restroom when it's over so you don't have to wait in line.