My Knee-Pit is Sweaty...JK!

Have you ever wondered what the back of an elbow or the back of a knee is called? Well, I have. At the moment I'm satisfied with calling them elbow and knee pits, but I'm pretty sure there's a more technical name for it...if anyone knows they should totally tell me because I'm not interested enough to look it up myself. I think I'll start posting pictures that I've drawn and am particularly found of, but the quality will be kind of crappy cuz i don't have a scanner...Does anyone know the correct way to type cuz? like 'cuz, or 'cause (looks like these ones right), or something like that? Why can't cuz be a word? Everyone says it! We should all write a petition. Also, what's with all these words that sound the same but have different meanings and spellings? Also words like read which can be read differently depending on the sentence. Now I'm just kind of rambling...oh well.P