Dictionary.net

one of a pair of nerves that arises from cervical spinal roots and passes down the thorax to innervate the diaphragm and control breathing

one of a pair of nerves that arises from cervical spinal roots and passes down the thorax to innervate the diaphragm and control breathing

The motor nerve of the diaphragm. The phrenic nerve fibers originate in the cervical spinal column (mostly C4) and travel through the cervical plexus to the diaphragm.