The placenta in the context of history and modern medical practice.

This is a brief summary of the development of our understanding of the anatomy and physiology of the human placenta. The article also traces the origin of some of the commonly used terminology that pertains to the placenta, and it makes reference to the major discoveries made in the understanding of human placentation. The legal implications for the current need of placental examination are traced and recommendations are made for future studies that might be conducted. Finally, questions are raised how to begin gaining some understanding of the mechanisms guiding the evolution of common placental features.