How does my bladder know...

When I am getting home? If I have a slight need to pee (male here) when I get home my bladder seems to get all uppity when I am turning the key in the door. I might have been driving around for an hour with a slight urge, but the minute I am within striking distance of the commode, suddenly Mr. Happy needs to put out a fire right now! How does he know?

I think this is what they call a conditioned reflex. Pavlov’s dogs and all that.

Your bladder doesn’t know. Your brain, which controls the bladder does.

I can’t believe I’m the first one to post this link.

And of course… I have no clue how the bladder knows (yeah, I know, I know, conditioned reflex) but I do sympathise.

Bladder: You should go to the bathroom in the next half hour or so

Me: yeah, sure, in a little while.

(little while later)

Bladder: You know, you should really go soon, like in the next 20 minutes or so

Me: Yeah, I guess this is a good stopping point, let’s head to the potty now.

(walks into bathroom)

Bladder: Oh good. WARNING I"M GONNA CUT LOOSE IN 5 SECONDS AND I DONT CARE THAT I TOLD YOU 20 MINUTES JUST 10 SECONDS AGO. SO I LIED, OKAY!!!

Underwear: EEEEEEKKKKKK!!! RIPPPPPPP!!!

(with apologies to Attrayant/Patty O’Furniture. Evidently there’s a PEE NOW force-field at the bathroom door).

Who knows what evil lurks in the hearts of men? The bladder knows!

I just wanted to say this is an excellent question and I was going to ask it myself soon. Besides the rather vague ideas of conditioning, there has to be some physiological process that kicks in and actually causes this.