Did you ever wonder why our marrow is located inside of our *bones*, #MedTwitter? There’s no a priori anatomical reason it should be sited there. Blood cells could form in our spleens & livers, as they do during our fetal lives; or elsewhere, as in some animals. Let’s discuss! /1 pic.twitter.com/PRayihuoj9
— David Steensma, MD (@DavidSteensma) November 29, 2023