crisis = singular, crises, plural
A 'crisis' is something that may become a disaster without immediate remedial action.
A financial crisis is when wall street and the banks are failing. An economic crisis is when there is high unemployment or a recession.
I would say a crisis is the result of a conflict. The conflict escalates into a crisis when it takes too long to solve the issue and other issues get intermingled into the conflict creating a crisis.
There is no difference between the reaction to a manmade disaster and the reaction to a natural disaster
conflict is between two or more parties and it manageable and short lasting while crisis is long lasting,involve systems and non manageable in some cases.
Contingency planning is where organisations prepare contingency plans in recognition of the fact that things do go wrong from time to time, so this is prepared BEFORE A CRISIS. It refers to being proactive, what-if's. Crisis Management involves identifying a crisis and planning a response, AFTER a crisis has occurred.
Realignments are typically associated with a major crisis or trauma in the nation's history
Risk management involves predicting potential threats and determining the best strategy to deal with those threats, crisis management involves dealing with threats after they have occurred.
I think what you refer to as 'trauma doctor' is trauma surgeon. As the name implies, they are surgeons. They do a number of surgeries (as in the operating room) to stabilize and treat the patients from traumatic injuries. ER physicians are trained to take care from everything from a cold to stabilize trauma patient, but they don't actually do surgeries (in the OR). They can do many procedures in the ER to help stabilize the patients so they can then go to the OR.
Trauma nurses and ER nurses essentially do the same thing -- which is to provide trauma care to patients in an emergency room setting. The main difference is that ER nurses are specialized to the emergency room, while trauma nurses are specialized to trauma. Even though the two areas mostly overlap, there are still trauma nurses who work outside of the emergency room, and ER nurses who do things besides handle trauma. It also gets confusing because ER nurses can work outside of the ER, too. But that is the main difference. Any additional detail about this is of course welcomed... I agree that in essence the two are very similar. To expand on the topic: like stated above "ER nurses do things besides handle trauma", ER nurses deal with every type of person that comes into the ER, whether it be a headache, Stubbed toe, or heart attack. The Trauma nurse is , usually, caring for only trauma patients. The trauma unit can be looked at almost like a specialty within ER, like the CCU can be divided into surgical ICU or Cardiac ICU.
The difference is that one can have a brain injury and not have brain damage. Essentially, brain damage is caused by injury or trauma to the brain. However, not every injury to the brain will cause brain damage.