How would an injury in the central nervous system affect the peripheral nervous system?

The way that an injury in the central nervous system affect the peripheral nervous system is : The peripheral nervous system would have no information to send to the muscles and glands. The pheriperal nervous system is the one that sends out the response from the our brain to move our muscle. Without it, the response that transferred by our brain will not be carried out by the rest of our body.

Geographic isolation.glad i could : )

Na+ loss through sweet plus the dilution has lowered na+ concentration outside of neurons, altering the na+ equilibrium potential. sodium exists more outside the cells than inside. when na+ is lost by sweat plus the dilution( because they drink a lot of water) changes the concentration outside the cell, forcing the water to enter the cell and attempt to balance the concentration inside/outside.the problem is that the abundance of water will cause the cells to swell. most cells can adapt, however, the brain cells can't that's why the runner has confusion and can't control the muscles.  if not treated and this occurs in less than 48 hours, it can be immediately fatal .