Branches

The thoracic sympathetic trunk has the following branches:

• somatic: pass out in the grey rami communicantes of each ganglion to join the associated spinal nerve
• visceral:
  • cardiac branches:
    • contributed to by preganglionic fibres from T1 to T5 segments
    • pass to the cardiac plexus
  • thoracic splanchnic nerves:
  • made up of preganglionic fibres which pass through the ganglia without synapsing
    • three in total: greater, lesser and least splanchnic nerves
    • pass to coeliac plexus within the abdomen
• vascular:
  • vasodilator fibres
  • pass along the outside of adjacent large blood vessels and ramify with them e.g. the aortic plexus
  • some fibres to distal structures e.g. the forearm and lower leg, pass with spinal nerves before associating with the local vasculature