Organ donation and donating your body to science are very different. One you help people who need an organ to live now, the other you give your carcass to researchers to poke and prod in order to develop new treatments, surgery techniques, etc. to improve the future of health care. Both are totally noble, but I highlighted this fact since most people who donate their bodies to science think they will become a cadaver in an anatomy lab somewhere. That is not always the case and, although truly beneficial to the future of medicine, you might be shocked what becomes of your body.