How does an injury to the spinal cord affect the nerves?

Depends on damage: The spinal cord serves as a conduit for information to/from the brain.If cord injury is minor(brief compression/shock) the information transfer may stop for a time & return after any swelling/etc.Is gone. If the injury kills a segment of the cord, the sensation below the segment is lost and voluntary control of muscles below the injury is gone (permanent paralysis). Reflex mvt may persist.

The spinal cord is : The main cable of nerve tracts to connect the brain to the nerves of the rest of the body except for the cranial nerves. An injury to the spinal cord can have a total or partial effect on nerve functions that can be permanent or temporary. The level at which the spinal cord injury occurs also affects which nerves will be involved as well. There are also several different patterns of cord injury.