TWEET IT - clicktotweet.com/aQNb5 The Sex-Ed class you never got in school! Why do men tend to wake up with "morning wood"? We look at the hard facts and some of the biology of an erection, to discover the mechanism behind this phenomenon. Written and created by Mitchell Moffit (twitter @mitchellmoffit) and Gregory Brown (twitter @whalewatchmeplz). TWITTER: www.twitter.com/AsapSCIENCE FACEBOOK: www.facebook.com/AsapSCIENCE Music by Mitchell Moffit www.mitchellmoffit.com www.twitter.com/mitchellmoffit www.facebook.com/mitchellmoffit Art by Gregory and Mitchell www.gregorybrownart.tumblr.com www.twitter.com/whalewatchmeplz Sources---- Sexual arousal: 1) joe.endocrinology-journals.org/content/186/3/411.full Sleep: 2) en.wikipedia.org/wiki/Sleep NPT and impotence: 3) www.ncbi.nlm.nih.gov/pubmed/3344559