Colleen falls down while mountain climbing and in the process bumps her head several times. Shortly after her fall she starts to experience headaches and blurred vision. Diagnostic tests at the hospital reveal an epidural hematoma (blood clot) in the temporo-parietal area that is expanding downward to press against the brain stem. For a few days Colleen remains unresponsive but is still alive. Eventually, she undergoes surgery which corrects the problem Explain what must have happened and why Colleen was able to survive her accident.