High Quality Content by WIKIPEDIA articles! The sympathetic trunks (sympathetic chain, gangliated cord) are a paired bundle of nerve fibers that run from the base of the skull to the coccyx. The sympathetic trunk travels in a downward direction from the skull, just lateral to the vertebral bodies. It interacts with the spinal nerves or their ventral rami by way of rami communicantes. The superior end of it is continued upward through the carotid canal into the skull, and forms a plexus on the internal carotid artery; the inferior part travels in front of the coccyx, where it converges with the other trunk at a structure known as the ganglion impar.