Termination in the stellate ganglion of axons arising from the hilar vegetative plexus of the lung. Peripheral reflex arcs.

In cats the right lung was removed by thoracotomy. After 24-48 h the right stellate ganglion, the communicating branches between the right stellate ganglion and the right vagus, as well as the portion of both vagus nerves below and above the communicating branches, were processed for electron-microscopic investigation. Degeneration of synaptic axon terminals in the anteromedial part of the stellate ganglia, occurring after removal of the ipsilateral lung, shows that processes of ganglion cells located in the terminal ganglia of the bronchial tree establish synapses in the stellate ganglia. These results speak in favour of the existence of peripheral reflex arcs in the autonomic nervous system. For the time being, the data are not sufficient to define a new pathway related to the autonomic ganglia.