Urgent Care departments are designed to provide urgent care that is not necessarily an emergency. As with the emergency room, there will be doctors that would stabilize the patient first, and then addresss any other issues. There will also be psychologists for mental health problems. If the mental health issue is significant, then they should be admitted into a mental health facility. With that said, there will be a number of options made available for those that need care now, but not in life threatening care.
Urgent Care is not a replacement for having an PCP. A Primary Care Physician will be able to build a history with you, and know what is most important to your needs. An urgent care doctor can not do that. If a bone is broke, then Urgent Care is the best solution though.