The answer to this question should be: formal group
A formal group is made by some people that were made to achieve a certain goal. This group mostly have a good structure and hierarchy. They work in a professional way so it might have some legal responsibility that was regulated by law.
In this case, the team performing open-heart surgery should have a leader that will determine what will they do when some options appear. Every member also has different roles and capability. They also have shared responsibility about the patient well being.
