 The collecting duct is the one structure that is going to travel from the cortex of the kidney all the way down to the medulla and ultimately to the renal papilla, where you can see we're going to dump urine. By the time it gets out of the collecting duct, it is urine, and we're going to dump that into the minor calyx. The collecting duct, the tubules start out with a simple cuboidal epithelium. It was in there. And eventually as they get farther down toward the renal papilla, they actually turn into a columnar epithelium. And there's some thinking that that might have to do with the characteristics of the medulla, the interstitial fluid found in the medulla, which is related to function, which we won't talk about. The column line, the collecting ducts, the ascending and descending loops of Henle, that's who we're going to see in the medulla from a histological perspective. How do you feel about your amazing kidneys? Do you like love them so much? Me too. Okay, I'll see you someday. Bye-bye.