They were formed during the 2nd Summit of the Five Worlds with Tsunade, 5th Hokage and Sanin of the leaf appointed as commander for her world's renowned medical skills and her role with the 2nd and 4th Great Ninja's wars. Although another person from Soul Society called Retsu Unohana was thought to be a candidate. However she was killed in action during the war with Soul Society and the Wandenreich and Chitsujo saying he reviving certain individuals if necessary, but later resurrected to help in the war efforts. All Medics in this Divisions are some best doctors/healers in their worlds, example being for her Tsunade for actions in 2nd and 4th great ninja wars, Dr Kurhea being renowned doctor in world and training the Strawhat pirate's Tony Tony Chopper, Though most of them lack fighting skills the and some even require protection. Tsunade, though, is one of the few exceptions, and was mainly chosen for her leadership skills.
List of Medics