Ethics are the big line for me. The human remains market is pretty infamous for having dubiously sourced parts - people who did not consent to having their body bought and sold.

The exhibit Body Worlds, which travels to different museums, is an example of this. Some of the bodies are likely executed prisoners, who did not consent to have their bodies displayed in this way. The US has a horrible history of treating indigenous peoples corpses with disrespect. Two of the children who died in the MOVE bombing ended up in a universities collection without the knowledge or consent of their relatives.

I would be willing to have a skeleton or preserved organs as teaching materials, if I knew the individual involved gave their consent for that use. If I ever can afford a hysterectomy I would love to preserve my uterus for that purpose. I’d love to be an articulated skeleton in a science classroom after I’m done here on earth.