Once the presynaptic fibers have synapsed, the postsynaptic sympathetic fibers reach their target structures by the most efficient path for the given region of the body. Postsynaptic sympathetic nerves have several possible routes depending on the location of their target organs. Many postsynaptic sympathetic fibers re-enter the ventral primary rami of spinal nerves via gray rami communicantes and get distributed to the body with the ventral and dorsal primary rami. Gray rami communicantes carry postsynaptic sympathetic fibers to every spinal nerve, allowing sympathetic innervation to reach all parts of the body, especially the blood vessels, sweat glands and arrector pili muscles.

Other postsynaptic sympathetic fibers leave the ganglia where they began and travel directly to their target organs. This is how postsynaptic sympathetic fibers reach the organs of the thorax. Finally, some postsynaptic sympathetic neurons form perivascular plexuses along blood vessels that supply a given area. The nerve fibers then ride along with the blood vessels to reach their targets. This is the method that postsynaptic sympathetic fibers use to reach target organs in the head as well as in the abdomen and pelvis.