The bundle of axons found in the spinal cord are called nerves. The axons, which are fibers, are called nerves when they are in the peripheral nervous system, such as when they are in the spine. If they are in the central nervous system, these bundles are called tracts.
Sensory nerves are located in the ganglion, while motor nerves are located in the gray matter of the spinal chord. Places where spinal nerves join together are called plexuses. Some examples of these plexuses are the lumbar plexus, the sacral plexus, the brachial plexus and the cervical plexus. Each particular plexus includes new combinations of fibers, such as the axillary nerve, radial nerve, median nerve and ulnar nerve.