The white rami communicantes are the preganglionic sympathetic outflow from the spinal cord. The cell bodies for the
preganglionic sympathetic myelinated fibers in the white rami communicantes lie in the ipsilateral (same sided) intermediolateral cell column in the spinal cord which extends from T1-L2. These rami also contain
general visceral afferent fibers (sensory from the organs) whose primary cell bodies reside
dorsal root ganglia (which then
synapse in the
dorsal horn). The preganglionic sympathetic fibers will enter into the sympathetic trunk and either synapse at the ganglion on the same level, or travel up or down the sympathetic trunk to arrive at the correct spinal level for their action. Once they synapse in the sympathetic ganglion in the
sympathetic trunk, they exit the trunk as gray rami to join the
spinal nerve and innervate the appropriate structure. Even though the sympathetic trunk extends below L2, there are no more white rami communicantes below L2 because the
intermediolateral cell column ends before this. The fibers of the sympathetic trunk above and below T1-L2 originate from white rami communicantes within T1-L2. Above and below T1-L2 there are only gray rami. Cell column are the important features of white rami communicates. ==Additional images==