The anatomy of the ferret paratracheal parasympathetic nerve-ganglion plexus.

Silver-impregnated preparations of the ferret paratracheal nerve-ganglion plexus were studied for description and quantitation of the general morphology of ganglia and nerve bundles and trunks. Most ganglia were found in one or two chains, separated by interganglionic nerve trunks, running the length of the trachea in close apposition to the trachealis muscle. Ganglia were flat, one cell deep, and characterized by irregular spacing and small and variable numbers of perikarya. Perifascicular, infrafascicular, and mixed types of ganglia were seen. The mean perikaryon density was 127 +/- 20/cm2 of trachealis muscle. In addition to connections to the interganglionic nerve trunk, more than 70% of ganglia were also apparently "connected" to nerve bundles running to the periphery and/or the center of the preparation, and the plexus seemed considerably more complex than originally described. There was no significant change in density, size or type, or connections of ganglia with nerve bundles in the cervical or thoracic trachea.