thoracic trunk (sympathetic, anatomy)
Last reviewed 01/2018
On each side of the spinal column within the bounds of the posterior mediastinum, there are twelve sympathetic ganglia within the sympathetic trunk. The most superior ganglion within each chain - the first thoracic ganglion - is continuous with the inferior cervical ganglion that lies superiorly. The most inferior ganglion within each chain - the twelfth thoracic ganglion - is continuous with the lumbosacral ganglia inferiorly. The first and occasionally second thoracic ganglia may fuse with the inferior cervical ganglion on each side to form the stellate ganglion.
As it traverses the thorax, the ganglia of each sympathetic trunk are positioned anterolateral to the heads of the ribs. The trunk is posterior to the costal pleura overlying the posterolateral surfaces of the lung. It lies posterolateral to the vertebral bodies but anterior to the intercostal nerves and vessels.
Each thoracic ganglion has contact with:
- the associated spinal nerve via grey and white rami communicantes
- the superior and inferior ganglia via fibres within the trunk
- thoracoabdominal tissues and organs via visceral branches