I am assuming that the wilderness survival situation is not one that was sought out, and thus getting back to civilization alive is ultimately desired.

Generally speaking, stay calm, and:

1. Immediate Life-saving First Aid
1A. Restore/Maintain ABC (airway, breathing, circulation)'s
1B. Stop Bleeding
1C. Treat For Shock
1D. Regulate Body Temperature

Regulating body temperature implies many things, such as shelter, fire, staying dry, out of the wind, etc. Simply put, exposure kills faster than thirst.

Treating infection can wait, as can treating pain, although treating for pain can make it easier to keep a wound from bleeding again, as a patient in pain has a tendency to move about, and stopping bleeding involves direct pressure and immobilization of the wounded area.

2. Rescue Signals

3. Immediate Subsistence Needs
3A. Water
3B. Food

Thirst kills faster than hunger.

2 and 3 are interchangeable, as opportunities to attract attention come and go, but opportunities must not be wasted, so rescue is given a higher priority.