The peripheral sympathetic nervous system arises from intermediolateral column of the spinal cord. The efferent preganglionic fibers exit the spinal cord through the ventral roots from T1 – L2. These fibers travel through the white rami communicantes to enter the sympathetic chain – 22 paired ganglia that lie along each side of the vertebral column. The preganglionic fibers travel along the sympathetic chain to synapse in ganglia within the sympathetic chain or peripheral ganglia.
The sympathetic chain lies within a fascial plane along the anterolateral aspect of the vertebral bodies. In 80% of people, the first thoracic and inferior cervical ganglia are fused together to form the stellate ganglion. The stellate ganglion is oval-shaped, measuring 1 inch long by 0.5 inch wide. The stellate ganglion lies anterior to the neck of the first rib and the C7 transverse process and anteromedial to the vertebral artery. It lies posterior to the common carotid artery, internal jugular vein, phrenic nerve and dome of the pleura. It is bound medially by the vertebral column, esophagus and trachea.