What is the actual scientific reason for morning wood?

I was once told that it was an evolutionary feature - that in prehistoric times cavemen used to sleep outdoors on hilly terrain. And sometimes in the night they would roll down hill to their death. Over time, they developed a self-defense mechanism called morning wood that acted like a kickstand, preventing them from rolling down hill at dawn's early light. Those who got morning wood survived and passed their genes on and now all men get it in the wee hours of morning - even though we don't sleep outside on hilly terrain any more!



I know that this crazy explanation can't possibly be true - so what's the real story, morning glory? Why do I have to stand there for 6 minutes and wait to pee every morning?

What is the actual scientific reason for morning wood?
Always remmember to put your kickstand down on the rocky terrane!
Reply:I THOUGHT IT WAS EITHER FROM DREAMING OR BECAUSE OF THE VIENS INVOLVED IN HAVING TO PEE CONSTRICTS THE OTHER VIENS MAKING THIS HAPPEN--SORRY DON'T KNOW TECHNICAL TERMS. ACTUALLY WHEN IT'S LIMP THE MUSCLES INSIDE ARE STIFF, WHEN ITS "MORNING WOOD" THE MUSCLES ARE LOOSE.
Reply:The level of testosterone peaks at about 5:00am. That is when a man gets the morning wood. If a man is healthy and has a good sleep, he will get it for sure. Those (at young age) who do not get it, should go for a check-up.
Reply:its called nocturnal tumescence, basically, the penis lives in a low oxygen state. Nature takes care of this by making sure the penis gets enough oxygenated blood through erections.
Reply:your explanation made me pee my pants. LOL! anyway, morning glory is intended by nature to prevent us guys from urinating and wetting the bed during sleep. you may have noticed that you can't pee when you are hard. this is exactly the principle at work here. cheers!
Reply:whoever told you that is an idiot, it is just the rush of blood from the heart because it has to pum harder than when you were sleeping, if that reason was true, why didnt women roll to their death?
Reply:It's God's way of keeping you from pissing your sheets. Be thankful...
Reply:ok here is the reason when you are asleep you are relaxed so your viens open up so you get a hard one ok that is the reason
Reply:I think in modern times morning wood is for to start the fire for first cup of coffee.....
Reply:Don't really know, but I think it has something to do with the daily cycle of hormone levels.
Reply:I had always heard it was do to the testosterone level in your bloodstream. It varies during the day and is at it's highest level early in the morning.