The cervical ganglia are paravertebral ganglia of the sympathetic nervous system. These emerging postganglionic nerves synapse with preganglionic nerves from the thoracic spinal cord. They consist of three paravertebral ganglia: superior cervical ganglion middle cervical ganglion inferior cervical ganglion. The inferior ganglion may be fused with the first thoracic ganglion to form a single structure, the stellate ganglion. Nerves emerging from cervical sympathetic ganglia contribute to the cardiac plexus, among other things. [ http://en.wikipedia.org/wiki/Cervical_ganglia ]