STRUCTURAL ORGANIZATION OF ENTERIC NERVOUS-SYSTEM IN HUMAN COLON

The organization of the Enteric Nervous System (ENS) was studied in th e human colon. Fragments of the whole colonic wall were either routine ly processed or Zinc-Iodide Osmium impregnated. Single-layer preparati ons were also obtained from some of the Zinc-Iodide Osmium-impregnated specimens. The results showed some differences in the organization of human colonic ENS from that of other mammals. In fact, the human subm ucous plexus was made up of three interconnected ganglionated networks arranged along three different planes. With respect to the myenteric plexus, its ganglia were large sized and irregularly shaped. Moreover, during the microdissection of the colonic wall, we found the absence of a cleavage plane between the circular and longitudinal muscle layer s; on the other hand the cleavage plane between mucosa and submucosa w as not immediately below the muscularis mucosae, but slightly deeper, since the innermost part of the submucosa remained adhering to overlyi ng layers.