PNS abbreviates the medical term meaning:
system made up of the cranial and spinal nerves;
PNS stands for peripheral nervous system. The peripheral nervous system is composed of bundles of impulse-carrying nerve cell fibers—12 pairs of cranial nerves and 31 pairs of spinal nerves—that transmit information to and from the central nervous system. This division of the nervous system is calledperipheral because the nerves extend to the outlying, or peripheral, parts of the body.