Eli5: How do bones and other organs know what shapes to grown into?

Question

Eli5: How do bones and other organs know what shapes to grown into?

In: 3675

Answer 1

You kinda have to take college level biology, chemistry and anatomy & physiology (A&P) to gain the ABCs of the medical world, with the latter being the meat of it all. The chemistry and biology are the jumping-off point.

Also, what stage at human development are we talking about? In utero? Adolescent? Post-injury as an adult?

If I had to give just one answer I would say that mesenchymal cells are at the center of it all, and they give rise to all the more specific types of osseous progenitor cells.